Changes

[ARM][MVE] Enable extending gathers
Enables the masked gather pass to create extending masked gathers.
Differential Revision: https://reviews.llvm.org/D72451

[lldb/DWARF/test] Freshen up debug_names tests
These tests used "clang -mllvm -accel-tables=Dwarf" as a way to 
guarantee that clang will emit the debug_names table. Unfortunately, a
change it clang made that insufficient (-gpubnames is required now too),
which rendered these tests ineffective. Since lldb automatically falls
back to the manual index, the tests didn't fail and this change went
largely unnoticed.
This patch updates the tests to really use debug_names (-gdwarf-5
-gpubnames) is the combination that works now, and it adds additional 
checks to ensure the section is actually emitted.
Fortunately, no regressions crept in while these tests were disabled.

[GlobalISel] Use more MachineIRBuilder helper methods
Reviewers: arsenm, nhaehnle
Subscribers: wdng, rovka, hiraditya, volkan, Petar.Avramovic,
llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72833

[ARM][LowOverheadLoops] Update liveness info
Recommitting e93e0d413f3a after reverting due to test failures, which 
will hopefully now be fixed. Original commit message:
After expanding the pseudo instructions, update the liveness info. We do
this in a post-order traversal of the loop, including its exit blocks
and preheader(s).
Differential Revision: https://reviews.llvm.org/D72131

[Hexagon] Remove unnecessary case in StringSwitch, NFC

Remove some SVN-specific code.
$URL$ is an SVN keyword substitution enabled via
`svn propset svn:keywords "URL" tools/clang/lib/Basic/Version.cpp`. Now
that we no longer use SVN, it's no longer being replaced by anything,
and we no longer offer svn exports. So remove the
$URL$-specific logic.
The "cfe" path prefix removal also no longer makes sense now that we're
on git: Both CLANG_REPOSITORY and LLVM_REPOSITORY are usually set to
https://github.com/llvm/llvm-project.git
So remove that too, and remove the "llvm" prefix removal for symmetry. 
With the github url, "llvm" _is_ found in the string, but not in the
place the function expected. Nobody noticed since the llvm repository
path is only used if CLANG_REVISION and LLVM_REVISION are different,
which in the git monorepo world they never should be.
(I might remove the "// Support LLVM in a separate repository" block in
a separate commit.)
Differential Revision: https://reviews.llvm.org/D72848

[GlobalISel] Pass MachineOperands into MachineIRBuilder helper methods
Reviewers: arsenm, aditya_nandakumar, aemerson
Subscribers: wdng, rovka, hiraditya, volkan, Petar.Avramovic,
llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72849

[GlobalISel] Don't arbitrarily limit a mask to 64 bits
Reviewers: arsenm
Subscribers: wdng, rovka, hiraditya, volkan, Petar.Avramovic,
llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72853

[Hexagon] Add preprocessor test for hexagonv66

AMDGPU/GlobalISel: Select DS GWS intrinsics

[lldb][NFC] Delete TestDataFormatterObjCNSDate.py
This test is just TestDataFormatterObjCNSData.py copied but without any
changes
(and it therefore doesn't even test NSDate).
It's also failing as NSData has been changed by me in 
4f244bba4f66b14382c446b62e122fa684b8db78.

[MC][test] Fix non-portable GNU diff option
Summary: This patch replaces the non-portable GNU diff option
`--strip-trailing-cr` with the POSIX `-b` option in two test files.
Reviewers: daltenty, jasonliu
Reviewed By: daltenty
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72745

AMDGPU/GlobalISel: Don't handle legacy buffer intrinsic

[llvm-exegesis][NFC] Refactor Mips tests fixtures into a base class.
Differential Revision: https://reviews.llvm.org/D72003

[llvm-exegesis][mips] Add RegisterAliasingTest unit test
Differential Revision: https://reviews.llvm.org/D72004

[Hexagon] Fix alignment info for __builtin_circ_lduh

[gn build] Port 6b357866496

[llvm] Make new pass manager's OptimizationLevel a class
Summary: The old pass manager separated speed optimization and size
optimization levels into two unsigned values. Coallescing both in an
enum in the new pass manager may lead to unintentional casts and
comparisons.
In particular, taking a look at how the loop unroll passes were
constructed previously, the Os/Oz are now (==new pass manager) treated
just like O3, likely unintentionally.
This change disallows raw comparisons between optimization levels, to 
avoid such unintended effects. As an effect, the O{s|z} behavior changes 
for loop unrolling and loop unroll and jam, matching O2 rather than O3.
The change also parameterizes the threshold values used for loop 
unrolling, primarily to aid testing.
Reviewers: tejohnson, davidxl
Reviewed By: tejohnson
Subscribers: zzheng, ychen, mehdi_amini, hiraditya, steven_wu,
dexonsmith, dang, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D72547

[lldb/Scripts] Remove swig_bot_lib/__init__.py

[GVN] introduce GVNOptions to control GVN pass behavior
There are a few global (cl::opt) controls that enable optional behavior
in GVN. Introduce GVNOptions that provide corresponding per-pass
instance controls.
That will allow to use GVN multiple times in pipeline each time with
different settings.
Reviewers: asbirlea, rnk, reames, skatkov, fhahn Reviewed By: fhahn
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72732

[LLDB] Add SymbolVendorWasm plugin for WebAssembly debugging
Add plugin class SymbolVendorWasm, with the logic to manage debug
symbols for Wasm modules.
Reviewers: clayborg, labath, aprantl, sbc100, teemperor
Reviewed By: labath
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D72650

[LLDB] Convert Plugins/ObjectFile/wasm/ObjectFileWasm.h to unix line
endings