[llvm] [AMDGPU] Fix unwanted LICM/CSE of llvm.amdgcn.pops.exiting.wave.id (PR #96190)

[Carl Ritson via llvm-commits]

https://github.com/perlfu approved this pull request.

LGTM

My only concern would be that there are things that need to be made aware of `S_MOV_B32_sideeffects` -- but after a quick search I could not see anything.

https://github.com/llvm/llvm-project/pull/96190