Changes

[mlir][ods] Custom builder with no params

Incorrect generation of custom build method without any params.

[mlir] Remove unneeded OpBuilder params. NFC.

These are now automatically prepended.

Revert "[AMDGPU] Insert waitcnt after returning from call"

This reverts commit ca907bfb57d8ad3ec3bcc2cff2abab7b1b933af6.

According to michel.daenzer,
> This completely broke the Mesa radeonsi driver on Navi 14. Xorg +
> xterm come up with major corruption & psychedelic colours.

Add missing namespace closure comment. NFCI.

Fixes clang-tidy llvm-namespace-comment warning.

Add missing namespace closure comments. NFCI.

Fixes some clang-tidy llvm-namespace-comment warnings.

[AArch64] Fix ldst optimization of non-immediate store offset

When matching store instruction for ldst opt, we should make sure store instr is in 'reg+imm' form as load instr,
otherwise, it will have assertion in isLdOffsetInRangeOfSt since it will use getImm() directly.

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D87905

recommit [HIP] Fix -gsplit-dwarf option

recommit e50465ecefc964e5700df26fc7e02a673eed085a with fix for
regression in lldb tests.

Two issues:

1. the directory part of original .dwo file was dropped
2. if the stem of the .dwo file contains '.', the last dot
and strings after that were removed

This recommit fixes those two issues.

[lldb] Remove lldb-perf remenant

Delete a file remaining from the deletion of lldb-perf in D64362.

Differential Revision: https://reviews.llvm.org/D88119

[mlir] Add insert before/after to list-like constructs in C API

Blocks in a region and operations in a block are organized in a linked list.
The C API only provides functions to append or to insert elements at the
specified numeric position in the list. The latter is expensive since it
requires to traverse the list. Add insert before/after functionality with low
cost that relies on the iplist elements being convertible to iterators.

Reviewed By: stellaraccident

Differential Revision: https://reviews.llvm.org/D88148

Fix regressioin in test dwp-separate-debug-file.cpp

[MLIR] Change default builders generated by TableGen to use TypeRange for result types

- Change the default builders to use TypeRange instead of ArrayRef<Type>
- Custom builders defined in LinalgStructuredOps now conflict with the default
  separate param ones, but the default collective params one is still needed. Resolve
  this by replicating the collective param builder as a custom builder and skipping
  the generation of default builders for these ops.

Differential Revision: https://reviews.llvm.org/D87926

[MLIR][NFC] Adopt use of TypeRange in build() methods.

- Use TypeRange instead of ArrayRef<Type> where possible.
- Change some of the custom builders to also use TypeRange

Differential Revision: https://reviews.llvm.org/D87944

Improve dynamic AST matching diagnostics for conversion errors

Currently, when marshaling a dynamic AST matchers, we check for the type
and value validity of matcher arguments at the same time for some matchers.
For instance, when marshaling hasAttr("foo"), the argument is first type
checked to ensure it's a string and then checked to see if that string can
locate an attribute with that name. Similar happens for other enumeration
conversions like cast kinds or unary operator kinds. If the type is
correct but the value cannot be looked up, we make a best-effort attempt
to find a nearby name that the user might have meant, but if one cannot
be found, we throw our hands up and claim the types don't match.

This has an unfortunate behavior that when the user enters something of
the correct type but a best guess cannot be located, you get confusing
error messages like:
Incorrect type for arg 1. (Expected = string) != (Actual = String).

This patch splits the argument check into two parts: if the types don't
match, give a type diagnostic. If the type matches but the value cannot
be converted, give a best guess diagnostic or a value could not be
located diagnostic. This addresses PR47057.

Update the documentation for the MLIR Dialect class (NFC)

[MLIR][NFC] Adopt use of BlockRange in place of ArrayRef<Block *>

- Use BlockRange in ODS generated builders as well as other places throughout the code

Differential Revision: https://reviews.llvm.org/D87955

Remove MLIR C-API explicit registration of standard ops.

* Added mlirRegisterAllDialects() to the python API until a more complete registration design emerges for it.

Differential Revision: https://reviews.llvm.org/D88155

[UpdateTestChecks] Remove bug-exposing test

Remove RISCV codegen tests for --include-generated-funcs because apparently
MachineOutliner has a bug on that target that is exposed by expensive-checks.

NFC: Remove dangling dep on MLIRStandardOps.

Was inadvertently left out of D88155.

[MBFIWrapper] Add a new function getBlockProfileCount

MBFIWrapper keeps track of block frequencies of newly created blocks and
modified blocks, modified block frequencies should also impact block profile
count. This class doesn't provide interface getBlockProfileCount, users can only
use the underlying MBFI to query profile count, the underlying MBFI doesn't know
the modifications made in MBFIWrapper, so it either provides stale profile count
for modified block or simply crashes on new blocks.

So this patch add function getBlockProfileCount to class MBFIWrapper to handle
new blocks or modified blocks.

Differential Revision: https://reviews.llvm.org/D87802

[clang]Test ensuring -fembed-bitcode passed to cc1 captures pre-opt bitcode.

This is important to not regress because it allows us to capture pre-optimization
bitcode and options, and replay the full optimization pipeline.

Differential Revision: https://reviews.llvm.org/D88114

Add optimal thread strategy

Add an optimal thread strategy to execute specified amount of tasks.
This strategy should prevent us from creating too many threads if we
occasionaly have an unexpectedly small amount of tasks.

Differential Revision: https://reviews.llvm.org/D87765

[Support/Path] Add path::is_absolute_gnu

Implements IS_ABSOLUTE_PATH from GNU tools.

C++17 is_absolute behavior is different the from the behavior defined by GNU
tools.

According to cppreference.com, C++17 states: "An absolute path is a path
that unambiguously identifies the location of a file without reference
to an additional starting location."

In other words, the rules are:
 1. POSIX style paths with nonempty root directory are absolute.
 2. Windows style paths with nonempty root name and root directory are
    absolute.
 3. No other paths are absolute.

GNU rules are:
 1. Paths starting with a path separator are absolute.
 2. Windows style paths are also absolute if they start with a character
    followed by ':'.
 3. No other paths are absolute.

On Windows style the path "C:\Users\Default" has "C:" as root name and "\"
as root directory.

Hence "C:" on Windows is absolute under GNU rules and not absolute under
C++17 because it has no root directory. Likewise "/" and "\" on Windows are
absolute under GNU and are not absolute under C++17 due to empty root name.

Related to PR46368.

Differential Revision: https://reviews.llvm.org/D87667

Add REQUIRES to embed-bitcode-noopt.ll

[EarlyCSE] Fix crash with expensive checks after D87691

D87691 reordered some checks, which turned out to be unsafe. More
specifically, when examining a store instruction, the check against
getOrCreateResult should be done before attempting to call
isSameMemGeneration. Otherwise a crash in MSSA walker can occur.

This patch restores the order of these calls to what it was originally.

Revert D87970 "[ThinLTO] Avoid temporaries when loading global decl attachment metadata"

This reverts commit ab1b4810b55279bcf6fdd87be74a403440be3991.

It caused an issue in llvm::lto::thinBackend for a -fsanitize=cfi build.

```
AbbrevNo is 0 => "Invalid abbrev number"
0  llvm::BitstreamCursor::getAbbrev (this=0x9db4c8, AbbrevID=4) at llvm/include/llvm/Bitstream/BitstreamReader.h:528
1  0x00007f5f777a6eb4 in llvm::BitstreamCursor::readRecord (this=0x9db4c8, AbbrevID=4, Vals=llvm::SmallVector of Size 0, Capacity 64, Blob=0x7ffcd0e26558) at
usr/local/google/home/maskray/llvm/llvm/lib/Bitstream/Reader/BitstreamReader.cpp:228
2  0x00007f5f796bf633 in llvm::MetadataLoader::MetadataLoaderImpl::lazyLoadOneMetadata (this=0x9db3a0, ID=188, Placeholders=...) at /usr/local/google/home/mas
ray/llvm/llvm/lib/Bitcode/Reader/MetadataLoader.cpp:1091
3  0x00007f5f796c2527 in llvm::MetadataLoader::MetadataLoaderImpl::getMetadataFwdRefOrLoad (this=0x9db3a0, ID=188) at llvm
lib/Bitcode/Reader/MetadataLoader.cpp:668
4  0x00007f5f796bfff3 in llvm::MetadataLoader::getMetadataFwdRefOrLoad (this=0xd31580, Idx=188) at llvm/lib/Bitcode/Reader
MetadataLoader.cpp:2290
5  0x00007f5f79638265 in (anonymous namespace)::BitcodeReader::parseFunctionBody (this=0xd312e0, F=0x9de758) at llvm/lib/B
tcode/Reader/BitcodeReader.cpp:3938
6  0x00007f5f79635d32 in (anonymous namespace)::BitcodeReader::materialize (this=0xd312e0, GV=0x9de758) at llvm/lib/Bitcod
/Reader/BitcodeReader.cpp:5408
7  0x00007f5f7f8dbe3e in llvm::Module::materialize (this=0x9b92c0, GV=0x9de758) at llvm/lib/IR/Module.cpp:442
8  0x00007f5f7f7f8fbe in llvm::GlobalValue::materialize (this=0x9de758) at llvm/lib/IR/Globals.cpp:50
9  0x00007f5f83b9b5f5 in llvm::FunctionImporter::importFunctions (this=0x7ffcd0e2a730, DestModule=..., ImportList=...) at
llvm/lib/Transforms/IPO/FunctionImport.cpp:1182
```

Break long line accidentally left in the previous commit

[Driver] Check whether Gentoo-specific configuration directory exists

Check whether /etc/env.d/gcc exists before trying to read from any
file from there. This saves a few OS calls on a non-Gentoo system.

Differential Revision: https://reviews.llvm.org/D87143

Re-apply https://reviews.llvm.org/D87921, was reverted to triage a PPC bot failure.

D87921 was reverted in commit b89059a31347dd09b55a96b99b3dbe38d7749908
as it was causing an unknown llvm PPC bot failure.  Reapplying the patch
after confirming that this is not responsible. Build bot failure:
https://reviews.llvm.org/D87921#2286644  which caused the revert.

The wrong placement of add pass with optimizations led to
-funique-internal-linkage-names being disabled.

Fixed the placement of the MPM.addpass for UniqueInternalLinkageNames to make it
work correctly with -O2 and new pass manager. Updated the tests to explicitly
check O0 and O1.

Differential Revision: https://reviews.llvm.org/D87921

Enhance TableGen so that backends can produce better error messages.

Modify SearchableTableEmitter.cpp to take advantage.
Clean up formatting and capitalization issues.

[ms] [llvm-ml] Add support for .radix directive, and accept all radix specifiers

Add support for .radix directive, and radix specifiers [yY] (binary), [oOqQ] (octal), and [tT] (decimal).

Also, when lexing MASM integers, require radix specifier; MASM requires that all literals without a radix specifier be treated as in the default radix. (e.g., 0100 = 100)

Reviewed By: thakis

Differential Revision: https://reviews.llvm.org/D87400

[TTI] add wrapper for matching vector reduction to reduce code duplication; NFC

I'm not sure what this means, but the order in which we try
the matches makes a difference on at least 1 regression test...

Fix include location (accidentally committed a local variation)

[X86] Improve demanded bits for X86ISD::BEXTR.

If the control is constant we can figure out exactly which bits
of the input are demanded.

Differential Revision: https://reviews.llvm.org/D88072

[SLP] Make HorizontalReduction::getOperationData take an Instruction* instead of a Value*. NFCI

All of the callers already have an Instruction *. Many of them
from a dyn_cast.

Also update the OperationData constructor to use a Instruction&
to remove a dyn_cast and make it clear that the pointer is non-null.

Differential Revision: https://reviews.llvm.org/D88132

Revert "[ms] [llvm-ml] Add support for .radix directive, and accept all radix specifiers"

This reverts commit 5dd1b6d612655c9006ba97a8b6487ded80719b48.

Update Phabricator doc to remove the warning on "arc land": tags a properly handled server side now

Document the `--verbatim` flag from arc to update the description for a phabricator revision

[lsan] On Fuchsia, don't use atexit hook for leak checks

Fuchsia's system libraries are instrumented and use the lsan
allocator for internal purposes.  So leak checking needs to run
after all atexit hooks and after the system libraries' internal
exit-time hooks.  The <zircon/sanitizer.h> hook API calls the
__sanitizer_process_exit_hook function at exactly the right time.

Reviewed By: vitalybuka, phosek

Differential Revision: https://reviews.llvm.org/D86171

[gn build] Allow option to build with asan/tsan/ubsan

Reviewed By: thakis

Differential Revision: https://reviews.llvm.org/D88056

[mlir][OpFormatGen] Update "custom" directives for attributes.

This tweaks the generated code for parsing attributes with a custom
directive to call `addAttribute` on the `OperationState` directly,
and adds a newline after this call. Previously, the generated code
would call `addAttribute` on the `OperationState` field `attributes`,
which has no such method and fails to compile. Furthermore, the lack
of newline would generate code with incorrectly formatted single line
`if` statements. Added tests for parsing and printing attributes with
a custom directive.

Reviewed By: mehdi_amini

Differential Revision: https://reviews.llvm.org/D87860

[AArch64][SVE] Fix frame offset calculation when d8 is saved.

If d8 is saved, the fp is not actually adjacent to the SVE
spills/allocations.  Fix the offset calculation to account for this.

Differential Revision: https://reviews.llvm.org/D88117

Add `breakpoint delete --disabled`: deletes all disabled breakpoints.

Differential Revision: https://reviews.llvm.org/D88129

[AMDGPU] Make ds fp atomics overloadable

Differential Revision: https://reviews.llvm.org/D87947

[IRSim] Adding IRSimilarityCandidate that contains a region of IRInstructionData.

The IRSimilarityCandidate is a container to hold a region of
IRInstructions and offer interfaces for the starting instruction, ending
instruction, parent function, length.  It also assigns a global value
number for each unique instance of a value in the region.

It also contains an interface to compare two IRSimilarity as to whether
they have the same sequence of similar instructions.

Tests for whether the instructions are similar are found in
unittests/Analysis/IRSimilarityIdentifierTest.cpp.

Recommit of: 4944bb190fed8861d4d043eaf45e3c1e12aa2dc5

Differential Revision: https://reviews.llvm.org/D86970

[PowerPC][PCRelative] Thread Local Storage Support for Local Dynamic

This patch is the initial support for the Local Dynamic Thread Local Storage
model to produce code sequence and relocation correct to the ABI for the model
when using PC relative memory operations.

Differential Revision: https://reviews.llvm.org/D87721

asan: Use `#if` to test CAN_SANITIZE_LEAKS

The `if (0)` isn't necessarily optimized out so as not to create
a link-time reference to LSan runtime functions that might not
exist.  So use explicit conditional compilation instead.

Reviewed By: phosek

Differential Revision: https://reviews.llvm.org/D88173

[scudo][standalone] Fix tests under ASan/UBSan

Fix a potential UB in `appendSignedDecimal` (with -INT64_MIN) by making
it a special case.

Fix the terrible test cases for `isOwned`: I was pretty sloppy on those
and used some stack & static variables, but since `isOwned` accesses
memory prior to the pointer to check for the validity of the Scudo
header, it ended up being detected as some global and stack buffer out
of bounds accesses. So not I am using buffers with enough room so that
the test will not access memory prior to the variables.

With those fixes, the tests pass on the ASan+UBSan Fuchsia build.

Thanks to Roland for pointing those out!

Differential Revision: https://reviews.llvm.org/D88170

Revert "[lsan] On Fuchsia, don't use atexit hook for leak checks"

This reverts commit 0caad9fe441d5ee562e96d8b30b5574b492a933a.
This reverts commit c96d0cceb684fa176b51d7df5f4f8370e2c983f4.

Causes linker errors which were not fixed by the subsequent commit
either:

/home/nikic/llvm-project/compiler-rt/lib/asan/asan_rtl.cpp:503: error: undefined reference to '__asan::InstallAtExitCheckLeaks()'

[AArch64][SVE] Add lowering for llvm frecpx

Add the functionality to lower frecpx for passthru variant

Reviewed By: paulwalker-arm

Differential Revision: https://reviews.llvm.org/D88032

Allow init_priority values <= 100 and > 65535 within system headers.

This also adds some bare-bones documentation for the attribute rather
than leaving it undocumented.

[lldb] Normalize paths in new test

The minidump-sysroot test I added in commit 20f84257 compares two paths
using a string comparison.  This causes the Windows buildbot to fail
because of mismatched forward slashes and backslashes.  Use
os.path.normcase to normalize before comparing.

[LoopTerminology][NFC] Fix formatting typo

Clean up test file, NFC

[PowerPC] Implement Vector signed/unsigned __int128 overloads for the comparison builtins

This patch implements Vector signed/unsigned __int128 overloads for the comparison builtins.

Differential Revision: https://reviews.llvm.org/D87804

[PowerPC] Implement the 128-bit vec_[all|any]_[eq | ne | lt | gt | le | ge] builtins in Clang/LLVM

This patch implements the vec_[all|any]_[eq | ne | lt | gt | le | ge] builtins for vector signed/unsigned __int128.

Differential Revision: https://reviews.llvm.org/D87910

Recommit [NFC] Refactor DiagnosticBuilder and PartialDiagnostic

This recommits 829d14ee0a6aa79c89f7f3d9fcd9d27d3efd2b91.

The patch was reverted due to a regression in some CUDA app
which was thought to be caused by this patch. However, investigation
showed that the regression was due to some other issues, therefore
recommit this patch.

[AArch64] Expand some vector of i64 reductions on NEON

With the exception of VECREDUCE_ADD, there are no NEON instructions to support vector of i64 reductions. This patch removes the Custom lowerings for those and adds some test coverage to confirm.

Differential Revision: https://reviews.llvm.org/D88161

[SelectionDAG][GISel] Make LegalizeDAG lower FNEG using integer ops.

Previously, if a floating-point type was legal, but FNEG wasn't legal,
we would use FSUB.  Instead, we should use integer ops, to preserve the
semantics.  (Alternatively, there's a compiler-rt call we could use, but
there isn't much reason to use that.)

It turns out we actually are still using this obscure codepath in a few
cases: on some targets, we have "legal" floating-point types that don't
actually support any floating-point operations.  In particular, ARM and
AArch64 are using this path.

The implementation for SelectionDAG is pretty simple because we can
reuse the infrastructure from FCOPYSIGN.

See also 9a3dc3e, the corresponding change to type legalization.

Also includes a "bonus" change to STRICT_FSUB legalization, so we can
lower a STRICT_FSUB to a float libcall.

Includes the changes to both LegalizeDAG and GlobalISel so we don't have
inconsistent results in the future.

Fixes https://bugs.llvm.org/show_bug.cgi?id=46792 .

Differential Revision: https://reviews.llvm.org/D84287

[JSON] Allow emitting comments in json::OStream

This isn't standard JSON, but is a popular extension.
It will be used to show errors in context, rendering pseudo-json for humans.

Differential Revision: https://reviews.llvm.org/D88103

[lld-macho] cleanup unimplemented-option warnings

Remove all spurious `HelpHidden` flags from  `lld/MachO/Options.td`. Add test for `HelpHidden` to `warnIfUnimplementedOption()` so that the empty `// handled elsewhere` case is unnecessary.

Reviewed By: #lld-macho, int3, smeenai

Differential Revision: https://reviews.llvm.org/D88160

[X86] Add a memory clobber to the bittest intrinsic inline asm. Get default clobbers from the target

I believe the inline asm emitted here should have a memory clobber since it writes to memory.

It was also missing the dirflag clobber that we use by default along with flags and fpsr. To avoid missing defaults in the future, get the default list from the target

Differential Revision: https://reviews.llvm.org/D88121

[lld-macho] handle options -search_paths_first, -search_dylibs_first

Differential Revision: https://reviews.llvm.org/D88054

[JSON] Facility to track position within an object and report errors.

This error model should be rich enough for most applications. It comprises:

- a name for the root object, so the user knows what we're parsing
- a path from the root object to the JSON node most associated with the error
- a local error message

This can be presented as an llvm::Error e.g.
  "expected string at ConfigFile.credentials[0].username"

It's designed to be cheap: Paths are a linked list of lightweight
objects on the stack. No heap allocations unless errors are encountered.

A subsequent commit will make use of this in the JSON-to-object
translation facilities: fromJSON and ObjectMapper.
However it's independent of these and can be used for e.g. validation alone.

Another subsequent commit will support showing the error in its context
within the parsed value.

Differential Revision: https://reviews.llvm.org/D88103

[NewPM][MSSA] Fix failures under NPM due to -enable-mssa-loop-dependency

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D88128

[NewPM][CGSCC] Handle newly added functions in updateCGAndAnalysisManagerForPass

This seems to fit the CGSCC updates model better than calling
addNewFunctionInto{Ref,}SCC() on newly created/outlined functions.
Now addNewFunctionInto{Ref,}SCC() are no longer necessary.

However, this doesn't work on newly outlined functions that aren't
referenced by the original function. e.g. if a() was outlined into b()
and c(), but c() is only referenced by b() and not by a(), this will
trigger an assert.

This also fixes an issue I was seeing with newly created functions not
having passes run on them.

Ran check-llvm with expensive checks.

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D87798

[NewPM] Add callbacks to PassBuilder to run before/after parsing a pass

This is in preparation for supporting -debugify-each, which adds a debug
info pass before and after each pass.

Switch VerifyEach to use this.

Reviewed By: ychen

Differential Revision: https://reviews.llvm.org/D88107

[JSON] Display errors associated with Paths in context

When an error occurs processing a JSON object, seeing the actual
surrounding data helps. Dumping just the node where the problem
was identified can be too much or too little information.

printErrorContext() shows the error message in its context, as a comment.
JSON values along the path to the broken place are shown in some detail,
the rest of the document is elided. For example:

```
{
  "credentials": [
    {
      "username": /* error: expected string */ 42,
      "password": "secret"
    },
    { ... }
  ]
  "backups": { ... }
}
```

Differential Revision: https://reviews.llvm.org/D88103

[libunwind] Combine dl_iterate_phdr codepaths for DWARF and EHABI

dl_iterate_phdr is used to search for unwind info provided by either
PT_GNU_EH_FRAME or PT_ARM_EXIDX. Most of the code between the two is
the same, so combine them, and factor out what's different into
checkForUnwindInfoSegment.

Details:
 - The FrameHeaderCache can now be enabled for ARM EHABI.
 - findUnwindSectionsByPhdr now finds the last PT_ARM_EXIDX rather than
   the first. There should only be one segment.
 - The dso_base and text_segment_length fields of UnwindInfoSections
   are now needed for dl_iterate_phdr when using EHABI, to hold the
   low and high PC values for a cache entry.

Reviewed By: compnerd, danielkiss, #libunwind, saugustine

Differential Revision: https://reviews.llvm.org/D87880

[libunwind] Optimize dl_iterate_phdr's findUnwindSectionsByPhdr

Currently, findUnwindSectionsByPhdr is slightly micro-optimized for the
case where the first callback has the target address, and is otherwise
very inefficient -- it decodes .eh_frame_hdr even when no PT_LOAD
matches the PC. (If the FrameHeaderCache is enabled, then the
micro-optimization only helps the first time unwind info is looked up.)

Instead, it makes more sense to optimize for the case where the
callback *doesn't* find the target address, so search for a PT_LOAD
segment first, and only look for the unwind info section if a matching
PT_LOAD is found.

This change helps on an Android benchmark with 100 shared objects,
where the DSO at the end of the dl_iterate_phdr list throws 10000
exceptions. Assuming the frame cache is disabled, this change cuts
about 30-40% off the benchmark's runtime.

Reviewed By: compnerd, saugustine, #libunwind

Differential Revision: https://reviews.llvm.org/D87881

[JSON] Add error reporting to fromJSON and ObjectMapper

Translating between JSON objects and C++ strutctures is common.
From experience in clangd, fromJSON/ObjectMapper work well and save a lot of
code, but aren't adopted elsewhere at least partly due to total lack of error
reporting beyond "ok"/"bad".

The recently-added error model should be rich enough for most applications.
It requires tracking the path within the root object and reporting local
errors at appropriate places.
To do this, we exploit the fact that the call graph of recursive
parse functions mirror the structure of the JSON itself.
The current path is represented as a linked list of segments, each of which is
on the stack as a parameter. Concretely, fromJSON now looks like:
  bool fromJSON(const Value&, T&, Path);

Beyond the signature change, this is reasonably unobtrusive: building
the path segments is mostly handled by ObjectMapper and the vector<T> fromJSON.
However the root caller of fromJSON must now create a Root object to
store the errors, which is a little clunky.

I've added high-level parse<T>(StringRef) -> Expected<T>, but it's not
general enough to be the primary interface I think (at least, not usable in
clangd).

All existing users (mostly just clangd) are updated in this patch,
making this change backwards-compatible is a bit hairy.

Differential Revision: https://reviews.llvm.org/D88103

Fix LLDB tweak in 62a47e994fcf5b73e29547d26cd9676b30cb69a3