Changes

[hwasan] Remove unused declaration shadowBase (NFC)

The function was introduced on Jan 23, 2019 in commit
73078ecd381b5ce95638c7a8e41fcabb6c27703a.

Its definition was removed on Oct 27, 2020 in commit
0930763b4baf926a39dd2d0571fd9e2102ec3831, leaving the declaration
unused.

[ValueMapper] Remove unused declaration remapFunction (NFC)

The function declaration with two parameters was introduced on Apr 16
2016 in commit f0d73f95c15f909c6034f1735632695248bb75a8 without a
corresponding definition.

[CodeGen] Use pred_empty (NFC)

[NFC] Reduce code duplication in binop processing in computeExitLimitFromCondCached

Handling of `and` and `or` vastly uses copy-paste. Factored out into
a helper function as preparation step for further fix (see PR48225).

Differential Revision: https://reviews.llvm.org/D91864
Reviewed By: nikic

[llvm-readobj] - Don't crash when relocation table goes past the EOF.

It is possible to trigger reading past the EOF by breaking fields like
DT_PLTRELSZ, DT_RELSZ or DT_RELASZ

This patch adds a validation in `DynRegionInfo` helper class.

Differential revision: https://reviews.llvm.org/D91787

[libc++] [www] Mark P0482 as "In Progress", as some parts of it are already implemented.

[clangd] Attempt at fixing ExternalIndex tests on windows

[lldb] [Process/FreeBSD] Add missing 'override' kws to POSIXStopInfo

Differential Revision: https://reviews.llvm.org/D91934

[lldb] [Process/Utility] Declare register overlaps between ST and MM

Explicitly declare register overlaps/invalidation between ST(i) and MMi
registers.

Differential Revision: https://reviews.llvm.org/D91728

[lldb] [test] Fix qRegisterInfo lldb-server tests to handle missing registers

Fix qRegisterInfo tests to handle Exx error response when querying
registers that are not supported on the platform in question.  This
is how FreeBSD and NetBSD platforms reporting missing registers right
now, and there certainly is value from verifying the remaining
registers.

This change fixes the test for FreeBSD but NetBSD has other regressions
that still need to be researched.

Differential Revision: https://reviews.llvm.org/D91922

[lldb] [Process/FreeBSDRemote] Fix regset names and related tests

Restore Linux-alike regset names for AVX/MPX registers
as TestLldbGdbServer seems to depend on them.  At the same time, fix
TestRegisters to be aware that they are not available on FreeBSD
and NetBSD, at least until we figure out a better way of reporting
unsupported register sets.

Differential Revision: https://reviews.llvm.org/D91923

[clang-tidy] Fix a nullptr-access crash in unused-raii-check.

I saw this crash in our internal production, but unfortunately didn't get
reproduced testcase, we likely hit this crash when the AST is ill-formed
(e.g. broken code).

Reviewed By: gribozavr2

Differential Revision: https://reviews.llvm.org/D91614

[lldb] Prevent 'process connect' from using local-only plugins

Add a 'can_connect' parameter to Process plugin initialization, and use
it to filter plugins to these capable of remote connections.  This is
used to prevent 'process connect' from picking up a plugin that can only
be used locally, e.g. the legacy FreeBSD plugin.

Differential Revision: https://reviews.llvm.org/D91810

[LoopFlatten] Widen IV, support ZExt.

I disabled the widening in fa5cb4b because it run in an assert, which was
related to replacing values with different types. I forgot that an extend could
also be a zero-extend, which I have added now. This means that the approach now
is to create and insert a trunc value of the outerloop for each user, and use
that to replace IV values.

Differential Revision: https://reviews.llvm.org/D91690

[DebugInfo] Refactor code for emitting DWARF expressions for FP constants

This patch moves the selection of the style used to emit the numbers
(DW_OP_implicit_value vs. DW_OP_const+DW_OP_stack_value) into
DwarfExpression::addUnsignedConstant. This logic is not FP-specific, and
it will be needed for large integers too.

The refactor also makes DW_OP_implicit_value (DW_OP_stack_value worked
already) be used for floating point constants other than float and
double, so I've added a _Float16 test for it.

Split off from D90916.

Differential Revision: https://reviews.llvm.org/D91058

[clangd] Second attempt at fixing windows buildbots

[llvm-readobj] - Stop using `unwrapOrError` in `DumpStyle<ELFT>::getGroups()`

With this we are able to diagnose possible issues much better and
don't exit on an error.

Differential revision: https://reviews.llvm.org/D91867

[SCEV] Fix incorrect treatment of max taken count. PR48225

SCEV makes a logical mistake when handling EitherMayExit in
case when both conditions must be met to exit the loop. The
mistake looks like follows: "if condition `A` fails within at most `X` first
iterations, and `B` fails within at most `Y` first iterations, then `A & B`
fails at most within `min (X, Y)` first iterations". This is wrong, because
both of them must fail at the same time.

Simple example illustrating this is following: we have an IV with step 1,
condition `A` = "IV is even", condition `B` = "IV is odd". Both `A` and `B`
will fail within first two iterations. But it doesn't mean that both of them
will fail within first two first iterations at the same time, which would mean
that IV is neither even nor odd at the same time within first 2 iterations.

We can only do so for known exact BE counts, but not for max.

Differential Revision: https://reviews.llvm.org/D91942
Reviewed By: nikic

[llvm-readelf/obj] - Fix the possible crash when dumping group sections.

It is possible to trigger a crash/misbehavior when the st_name field of
the signature symbol goes past the end of the string table.

This patch fixes it.

Differential revision: https://reviews.llvm.org/D91943

[AST] Build recovery expression by default for all language.

The dependency mechanism for C has been implemented, and we have rolled out
this to all internal users, didn't see crashy issues, we consider it is stable
enough.

Differential Revision: https://reviews.llvm.org/D89046

[mlir][Linalg] NFC - Factor out Linalg functionality for shape and loop bounds computation

This revision refactors code used in various Linalg transformations and makes it a first class citizen to the LinalgStructureOpInterface. This is in preparation to allowing more advanced Linalg behavior but is otherwise NFC.

Differential revision: https://reviews.llvm.org/D91863