Changes

[MachineCombine] add a hook for resource length limit

Fix strict aliasing warning in msan.cpp

Use internal_memcpy instead.

Differential Revision: https://reviews.llvm.org/D80732

Improve SmallPtrSetImpl::count implementation

Relying on the find method implies a roundtrip to the iterator world, which is
not costless because iterator creation involves a few check to ensure the
iterator is in a valid position (through the SmallPtrSetIteratorImpl::AdvanceIfNotValid
method). It turns out that the result of SmallPtrSetImpl::find_imp is either
valid or the EndPointer, so there's no need to go through that abstraction,
and the compiler cannot guess it.

Differential Revision: https://reviews.llvm.org/D80708

[ASTMatchers] Force c++ unittests to specify correct language standard

Force the unittests on c++ code for matchers to specify the correct standard.

Reviewed By: gribozavr2

Differential Revision: https://reviews.llvm.org/D80884

[DebugInfo][CallSites] Remove decl subprograms from 'retainedTypes:'

After the D70350, the retainedTypes: isn't being used for the purpose
of call site debug info for extern calls, so it is safe to delete it
from IR representation.
We are also adding a test to ensure the subprogram isn't stored within
the retainedTypes: from corresponding DICompileUnit.

Differential Revision: https://reviews.llvm.org/D80369

AArch64: materialize large stack offset into xzr correctly.

When a stack offset was too big to materialize in a single instruction, we were
trying to do it in stages:

    adds xD, sp, #imm
    adds xD, xD, #imm

Unfortunately, if xD is xzr then the second instruction doesn't exist and
wouldn't do what was needed if it did. Instead we can use a temporary register
for all but the last addition.

[llvm-readobj] - Improve error reporting for hash tables.

This improves the next points for broken hash tables:

1) Use reportUniqueWarning to prevent duplication when
   --hash-table and --elf-hash-histogram are used together.

2) Dump nbuckets and nchain fields. It is often possible
   to dump them even when the table itself goes past the EOF etc.

Differential revision: https://reviews.llvm.org/D80373

[StructurizeCFG] Fix region nodes ordering

This is a reimplementation of the `orderNodes` function, as the old
implementation didn't take into account all cases.
The new implementation uses SCCs instead of Loops to take account of
irreducible loops.

Fix PR41509

Differential Revision: https://reviews.llvm.org/D79037

[llvm-readelf] - Add explicit braces. NFC.

Should fix the BB (http://lab.llvm.org:8011/builders/clang-ppc64le-rhel/builds/3907/steps/build%20stage%201/logs/stdio):

llvm-readobj/ELFDumper.cpp:4708:5: error: add explicit braces to avoid dangling else [-Werror,-Wdangling-else]
    else
    ^

[llvm-readelf] - Add explicit braces again. NFC.

Partially reverts feee98645dde4be31a70cc6660d2fc4d4b9d32d8.

Add explicit braces to a different place to fix
"error: add explicit braces to avoid dangling else [-Werror,-Wdangling-else]"

[DebugInfo] Separate fields with commas in headers of .debug_pub* tables (1/3).

For most tables, we already use commas in headers. This set of patches
unifies dumping the remaining ones.

Differential Revision: https://reviews.llvm.org/D80806

[DebugInfo] Separate fields with commas in headers of compile units (2/3).

For most tables, we already use commas in headers. This set of patches
unifies dumping the remaining ones.

Differential Revision: https://reviews.llvm.org/D80806

[DebugInfo] Separate fields with commas in headers of type units (3/3).

For most tables, we already use commas in headers. This set of patches
unifies dumping the remaining ones.

Differential Revision: https://reviews.llvm.org/D80806