[llvm] [AMDGPU]: Accept constant zero bytes in v_perm OrCombine (PR #66533)

[Matt Arsenault via llvm-commits]

https://github.com/arsenm commented:

Instead of rebasing, you should push new commits and merge commits. I have no idea what was in the previous version now 

https://github.com/llvm/llvm-project/pull/66533