[llvm] [clang] [AMDGPU] Add InstCombine rule for ballot.i64 intrinsic in wave32 mode. (PR #71556)

[via cfe-commits]

dyung wrote:

@vpykhtin the test you modified builtins-amdgcn-wave32.cl seems to be failing on a few bots. Can you take a look?

https://lab.llvm.org/buildbot/#/builders/188/builds/40541
https://lab.llvm.org/buildbot/#/builders/91/builds/21847
https://lab.llvm.org/buildbot/#/builders/98/builds/31671
https://lab.llvm.org/buildbot/#/builders/139/builds/57289


https://github.com/llvm/llvm-project/pull/71556