Changes

Update branch names from master -> main

[NFC][SimplifyCFG] PerformBranchToCommonDestFolding(): fix instruction name preservation

NewBonusInst just took name from BonusInst, so BonusInst has no name,
so BonusInst.getName() makes no sense.
So we need to ask NewBonusInst for the name.

[NFC][SimplifyCFG] fold-branch-to-common-dest.ll: reduce complexity of @pr48450* test

We don't need that many iterations there,
having less iterations helps alive2 verify it.

[NFC][SimplifyCFG] PerformBranchToCommonDestFolding(): move instruction cloning to after CFG update

This simplifies follow-up patch, and is NFC otherwise.

[SimplifyCFG] FoldBranchToCommonDest(): re-lift restrictions on liveout uses of bonus instructions

I have previously tried doing that in
b33fbbaa34f0fe9fb16789afc72ae424c1825b69 / d38205144febf4dc42c9270c6aa3d978f1ef65e1,
but eventually it was pointed out that the approach taken there
was just broken wrt how the uses of bonus instructions are updated
to account for the fact that they should now use either bonus instruction
or the cloned bonus instruction. In particluar, all that manual handling
of PHI nodes in successors was just wrong.

But, the fix is actually much much simpler than my initial approach:
just tell SSAUpdate about both instances of bonus instruction,
and let it deal with all the PHI handling.

Alive2 confirms that the reproducers from the original bugs (@pr48450*)
are now handled correctly.

This effectively reverts commit 59560e85897afc50090b6c3d920bacfd28b49d06,
effectively relanding b33fbbaa34f0fe9fb16789afc72ae424c1825b69.

Revert "[GlobalISel] LegalizerHelper - Extract widenScalarAddoSubo method"

This reverts commit 2bb92bf451d7eb2c817f3e5403353e7c0c14d350.

Dependent patch broke UBSan on Android:
3dedad475da45c05bc4f66cd14e9f44581edf0bc

Revert "[AArch64][GlobalISel] Implement widenScalar for signed overflow"

This reverts commit 541d98efa222b00e16c67348810898c2fa11f398.

Reason: Dependent patch 3dedad475da45c05bc4f66cd14e9f44581edf0bc broke
UBSan on Android: http://lab.llvm.org:8011/#/builders/77/builds/3082

Revert "[AArch64][GlobalISel] Make G_USUBO legal and select it."

This reverts commit 3dedad475da45c05bc4f66cd14e9f44581edf0bc.

Broke UBSan on Android:
http://lab.llvm.org:8011/#/builders/77/builds/3082

More details at: https://reviews.llvm.org/D95032

[Matrix] Propagate shape information through fneg

Similar to binary operators like fadd/fmul/fsub, propagate shape info
through unary operators (fneg is the only one?).

Differential Revision: https://reviews.llvm.org/D95252

[mlir][Linalg] Make Fill operation work on tensors.

Depends on D95109

[RISCV] Add more cmov isel patterns to handle seteq/ne with a small non-zero immediate.

Similar to our free standing setcc patterns, we can use ADDI to
subtract the immediate from the other operand. Then the cmov
can check if the result is zero or non-zero.

Reviewed By: mundaym

Differential Revision: https://reviews.llvm.org/D95169

[RGT][ADT] Remove test assertion that will not be executed

Found by the Rotten Green Tests project.

Differential Revision: https://reviews.llvm.org/D95255

[lldb] FixFileSystem::GetExternalPath for VFS API change

[RGT] Don't use EXPECT* macros in a subprocess that exits by signalling

Found by the Rotten Green Tests project.

Differential Revision: https://reviews.llvm.org/D95256

[RGT][TextAPI] Remove a zero-trip loop and the assertions within it

Found by the Rotten Green Tests project.

Differential Revision: https://reviews.llvm.org/D95259