[llvm] [AMDGPU] SIWholeQuadMode: avoid execz effects in exact regions (PR #101157)

[Piotr Sobczak via llvm-commits]

https://github.com/piotrAMD commented:

Can you pre-commit the test?

The patch looks good to me. The bug makes me slightly worried that there might be other cases with exec = 0 that we are not detecting in the pass.

https://github.com/llvm/llvm-project/pull/101157