Changes

Removed c_compiler and cxx_compiler options from OpenMPBuilder
They are redundant with environment variables CC and CXX that are used 
elsewhere, and are less versatile (e.g., don't allow compiler wrappers 
like ccache).

Revert "        Reapply af57dbf12e54 "Add support for options
-frounding-math, ftrapping-math, -ffp-model=, and
-ffp-exception-behavior=""
This reverts commit cdbed2dd856c14687efd741c2d8321686102acb8. Build
break on Windows (lit fail)

[LangRef] make per-element poison behavior explicit
As discussed in D70246 and PR43958: 
https://bugs.llvm.org/show_bug.cgi?id=43958
The LangRef seems ambiguous about the behavior of poison with respect to
vectors.
We could go further with text and/or examples - suggestions welcome.
Also, see discussion on llvm-dev; 
http://lists.llvm.org/pipermail/llvm-dev/2019-November/137243.html
Differential Revision: https://reviews.llvm.org/D70641

[X86] Add missing break to the end of the last case in a switch. NFC

[VectorUtils] API for VFShape, update VFInfo.
Summary: This patch introduces an API to build and modify vector shapes.
The validity of a VFShape can be checked with the
`hasValidParameterList` method, which is also run in an assertion each 
time a VFShape is modified.
The field VFISAKind has been moved to VFInfo under the assumption that 
different ISAs can map to the same VFShape (as it can be in the case of
vector extensions with the same registers size, for example AVX and 
AVX2).
Reviewers: sdesmalen, jdoerfert, simoll, hsaito
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D70513

[OPENMP50]Add support for if clause for simd part in taskloop simd
directive.
According to OpenMP 5.0, the `if` clause can be applied to simd 
subdirective in the combined directive.

[MIBundle] Remove unused/obsolete MIOperands/ConstMIOperands (NFC).
Those iterators are unused and the respective iterators from 
MachineInstr should be used (e.g. MachineInstr::operands(), 
https://llvm.org/doxygen/classllvm_1_1MachineInstr.html#aef0e7e42e45e15f86b2a122b56ab829c)
Reviewers: evandro, t.p.northover, paquette, MatzeB, arsenm, ab
Reviewed By: ab
Differential Revision: https://reviews.llvm.org/D70560

Add --strip-trailing-cr to compression tests so they pass on Windows.

[DWARF5][Debuginfo] Compilation unit type (DW_UT_skeleton) and root DIE
(DW_TAG_compile_unit) do not match.
That patch fixes incompatible compilation unit type (DW_UT_skeleton) and
root DIE (DW_TAG_compile_unit) error.
cat split-dwarf.cpp int main()
{
 int a = 1;
 return 0;
}
clang++ -O -g -gsplit-dwarf -gdwarf-5 split-dwarf.cpp; llvm-dwarfdump
--verify ./a.out | grep skeleton error: Compilation unit type
(DW_UT_skeleton) and root DIE (DW_TAG_compile_unit) do not match.
The fix is to change DW_TAG_compile_unit into DW_TAG_skeleton_unit when
skeleton file is generated.
Differential Revision: https://reviews.llvm.org/D70880

[LLDB] Actually fix the win-i386-line-table.s test when executed on
windows
The previous fix attempt, in 62a635e864e0, used too much escaping for
the backslashes.
But instead of using regexes to match both path separator forms, remove
the path altogether to unify the output from the testcase between
platforms.

[NFC][InstCombine] Autogenerate check lines in a few tests
These files are potentially affected by Negator (D68408) patch.

[compiler-rt] FuzzedDataProvider: do not call memcpy on empty vector.
Summary: Some versions of memcpy mark pointer arguments as __nonnull,
that triggers UBSan errors even when the length passed is 0.
Reviewers: manojgupta, metzman
Subscribers: dberris, #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D71031
[compiler-rt] FDP: assert that num_bytes_to_consume == 0 when size == 0.

[lit] Document the undocumented pre-defined substitutions

Revert "Add --strip-trailing-cr to compression tests so they pass on
Windows."
This reverts commit d6cbc9528d46d30416a6f9cd6c8570b704a0bd33.
It causes the tests to fail on AIX.

Bug 43965 - Value of _MSVC_LANG doesn't match MSVC++ VS2019
/std:c++latest mode
Summary: The patch adds correct value of _MSVC_LANG to match with MSVC++
VS2019 /std:c++latest mode.
    Bugzilla - Bug 43965
   https://bugs.llvm.org/show_bug.cgi?id=43965
    The value for a MS specific macro differs from Microsoft starting
with VS2019 in /std:c++latest mode.
    -bash-4.2$ cat msvclang.cpp
   _MSVC_LANG
    -bash-4.2$ cl /std:c++latest -E msvclang.cpp
   Microsoft (R) C/C++ Optimizing Compiler Version 19.20.27508.1 for x64
   Copyright (C) Microsoft Corporation.  All rights reserved.
    /std:c++latest is provided as a preview of language features from
the latest C++
   working draft, and we're eager to hear about bugs and suggestions for
improvements.
   However, note that these features are provided as-is without support,
and subject
   to changes or removal as the working draft evolves. See
   https://go.microsoft.com/fwlink/?linkid=2045807 for details.
    msvclang.cpp
    201705L
    -bash-4.2$ clang-cl /std:c++latest -E  msvclang.cpp
   201704L
Reviewers: rnk
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D70996

Revert "[OpenMP50] Add parallel master construct, by Chi Chun Chen."
This reverts commit 713dab21e27c987b9114547ce7136bac2e775de9.
Tests do not pass on Windows.

[ThinLTO] Fix importing of writeonly variables in distributed ThinLTO
Summary: D69561/dde5893 enabled importing of readonly variables with
references, however, it introduced a bug relating to
importing/internalization of writeonly variables with references.
A fix for this was added in D70006/7f92d66. But this didn't work in 
distributed ThinLTO mode. The reason is that the fix (importing the 
writeonly var with a zeroinitializer) was only applied when there were 
references on the writeonly var summary. In distributed ThinLTO mode, 
where we only have a small slice of the index, we will not have the 
references on the importing side if we are not importing those 
referenced values. Rather than changing this handshaking (which will 
require a lot of other changes, since that's how we know what to import 
in the distributed backend clang invocation), we can simply always give 
the writeonly variable a zero initializer.
Reviewers: evgeny777, steven_wu
Subscribers: mehdi_amini, inglorion, hiraditya, dexonsmith, arphaman,
llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D70977

[llvm-symbolizer] Support debug file lookup using build ID
Build ID is a protocol for looking up debug files that's already 
supported by various tools including debuggers. For example, when 
locating debug files, gdb would check the following directories:
- /usr/lib/debug/.build-id/ab/cdef1234.debug
- /usr/bin/ls.debug
- /usr/bin/.debug/ls.debug
- /usr/lib/debug/usr/bin/ls.debug
llvm-symbolizer currently consults all of these except for build ID 
based one. This patch implements support for build ID lookup. The set of
debug directories to search is specified by the new option:
--debug-file-directory, whose name matches the debug-file-directory 
variable used by gdb for the same purpose.
Differential Revision: https://reviews.llvm.org/D70759

Upstream debugserver arm64e support.
The changes are minor; primarily debugserver needs to go through 
accessor functions/macros when changing pc/fp/sp/lr, and debugserver 
needs to clear any existing pointer auth bits from values in two cases. 
debugserver can fetch the number of bits used for addressing from a
sysctl, and will include that in the qHostInfo reply.  Update qHostInfo
documentation to document it.

Add help text for parray and poarray aliases.

[llvm] Fixing MIRVRegNamerUtils to properly handle 2+
MachineBasicBlocks.
An interplay of code from D70210, along with code from the 
Value-Numbering-esque hash-based namer from D70210, as well as some 
crusty code from the original MIR-Canon code lead to multiple causes of 
failure when canonicalizing or renaming vregs for MIR with multiple 
basic blocks. This patch fixes those issues while deleting some no 
longer needed code and adding a nice diamond test case to boot.
Differential Revision: https://reviews.llvm.org/D70478

Add parray example for lldb, vrs. *ptr@count gdb cmd.

[clang][IFS] Adding support for new clang interface stubs decl types.
NamespaceAliasDecl UnresolvedUsingTypenameDecl CXXDeductionGuideDecl 
ConstructorUsingShadowDecl
Differential Revision: https://reviews.llvm.org/D70728

[analyzer] Fix more ObjC accessor body farms after 2073dd2d.
Fix a crash when constructing a body farm for accessors of a property 
that is declared and @synthesize'd in different (but related) interfaces 
with the explicit ivar syntax.
This is a follow-up for 0b58b80e.

Revert "Reland [AArch64][MachineOutliner] Return address signing for
outlined functions"
This reverts commit 02760b750b2ffcc0e2f5d78ecb137c80930c42c3.
The original commit is not asan clean. 
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fast/builds/37147/steps/check-llvm%20asan/logs/stdio

[lldb/Reproducers] Override capture with LLDB_CAPTURE_REPRODUCER env var
Make it possible to override reproducer capture with the 
LLDB_CAPTURE_REPRODUCER environment variable.
The goal of this change is twofold.
(1) I want to be able to enable capturing reproducers during regular
   test runs, both locally and on the bots. To do so I need a way to
   force capture. I cannot do this through the Python API, because
   reproducer capture must be enabled *before* the debugger
   initialized, which happens automatically when doing `import lldb`.
(2) I want to provide an escape hatch for when reproducers are enabled
   by default. Downstream we have reproducer capture enabled by default
   in the driver.
This patch solves both problems by overriding the reproducer mode based 
on the environment variable. Acceptable values are 0/1 and ON/OFF.

[lldb/Reproducers] Propagate LLDB_CAPTURE_REPRODUCER to the test suite

[clangd] NFC, add getLangOpts helper to ParsedAST
The addition of the helper is split out from
https://reviews.llvm.org/D69543 as suggested by Kadir. I also updated
the existing uses to use the new API.

[clangd]  Add a tweak refactoring to wrap Objective-C string literals in
`NSLocalizedString` macros
The commit adds a refactoring to Clangd that mimics the existing
refactoring action in Xcode that wraps around an Objective-C string
literal in an NSLocalizedString macro.
Differential Revision: https://reviews.llvm.org/D69543

gn build: Merge 27f12444575

[clang][IFS] Ignoring -Xlinker/-Xclang arguments in InterfaceStubs pass
for now.
Many of the inputs to clang driver toolchain tools can be things other 
than files such as -Xclang and -Xlinker arguments. For now we don't take 
such tool pass-through type arguments (although having an -Xifs would be
nice to have to replace things like -emit-merged-ifs). So because for
the moment we are not doing any sort of argument pass-through, I am
going to have InterfaceStubs Merger ignore any non-file type input
arguments.
Differential Revision: https://reviews.llvm.org/D70838

[GlobalISel] Fix compiler crash lowering G_LOAD in AArch64.
Patch by Daniel Rodríguez Troitiño.
Differential Revision: https://reviews.llvm.org/D70794

Reland [AArch64][MachineOutliner] Return address signing for outlined
functions
Summary: Reland after fixing an ASan failure by stopping outlining early
if the constraints for return address signing removed too many outlining
candidates.
During AArch64 frame lowering instructions to enable return address 
signing are inserted into functions if needed. Functions generated
during machine outlining don't run through target frame lowering and
hence are missing such instructions.
This patch introduces the following changes:
1. If not all functions that potentially participate in function
outlining agree
  on their return address signing scope and their return address signing
key,
  outlining is disabled for these functions. 2. If not all functions
that potentially participate in function outlining agree
  on their support for v8.3A features, outlining is disabled for these
  functions. 3. If an outlining candidate would outline instructions
that modify sp in a way
  that invalidates return address signing, outlining is disabled for
that
  particular candidate. 4. If all candidate functions agree on the
signing scope, signing key and their
  support for v8.3 features, the outlined function behaves as if it had
the
  same scope and key attributes and as if it would provide the same
v8.3A
  support as the original functions.
Reviewers: ostannard, paquette
Reviewed By: ostannard
Subscribers: kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D70635

[lldb/Reproducers] Add missing instrumentation for SBFile
This was properly captured by the instrumentation framework when running 
TestRunCommandInterpreterAPI.py in capture-mode.

Clear out the python class name in OptionParsingStarted for the
OptionGroupPythonClassWithDict options class.  This value was hanging
around so for instance if you made a scripted breakpoint resolver, then
went to set another breakpoint, it would still think you had passed in a
class name and the breakpoint wouldn't do what you expected.

[X86] Remove override of shouldUseStrictFP_TO_INT for fp80. NFC
I suspect this became unnecessary after r354161. Prior to that we may
have been going through the default expansion of FP_TO_UINT on 64-bit
targets and then ending up back in Custom X86 handling to handle the
FP_TO_SINT for it. Now we just Custom handle the FP_TO_UINT directly. We
already need to handle it for 32-bit mode during type legalization so we
wouldn't save any code by using the default expansion on 64-bit.

[lldb/Reproducers] Add missing instrumentation for SBFile (2/2)
Found another issue while running TestDefaultConstructorForAPIObjects.

[lldb/Reproducers] Don't instrument SBFileSpec::GetPath
This method uses a char* and length as output arguments and the 
reproducer instrumentation doesn't know how to deal with that (yet).

[c++17] Fix assert / wrong code when passing a noexcept pointer to
member function to a non-noexcept pointer to member non-type template
parameter.

Properly convert all declaration non-type template arguments when
forming non-type template parameter values.

[MachineCopyPropagation] Extend MCP to do trivial copy backward
propagation
Summary: This patch mainly do such transformation
```
$R0 = OP ...
... // No read/clobber of $R0 and $R1
$R1 = COPY $R0 // $R0 is killed
``` Replace $R0 with $R1 and remove the COPY, we have
```
$R1 = OP ...
``` This transformation can also expose more opportunities for existing 
copy elimination in MCP.
Differential Revision: https://reviews.llvm.org/D67794

[clangd] Add xref for macro to static index.
Summary: This adds the references for macros to the SymbolCollector
(used for static index). Enabled if `CollectMacro` option is set.
Reviewers: hokein
Subscribers: ilya-biryukov, MaskRay, jkorous, arphaman, kadircet,
cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D70489

[fix][unittests][llvm] Fix running unit tests without assertions. [NFCI]

[Signal] Allow one-shot SIGPIPE handler to be reached
As SIGPIPE is no longer in the IntSigs array, handle SIGPIPE before 
handling any interrupt signals.
Thanks to Alexandre Ganea for pointing out the issue here.

[AArch64][SVE] Add intrinsics and patterns for logical predicate
instructions
Add instrinics and patters for the following logical predicate
instructions:
-- and, ands, bic, bics, eor, eors
-- sel
-- orr, orrs, orn, orns, nor, nors, nand, nads

Add a default copy-assignment or copy-constructor for -Wdeprecated-copy
warnings.

Revert "[MachineCopyPropagation] Extend MCP to do trivial copy backward
propagation"
This reverts commit 75b3a1c318ccad0f96c38689279bc5db63e2ad05, since it 
breaks bootstrap build.

Removed c_compiler and cxx_compiler options from OpenMPBuilder
They are redundant with environment variables CC and CXX that are used 
elsewhere, and are less versatile (e.g., don't allow compiler wrappers 
like ccache).