[llvm] [InstCombine][AMDGPU] Disable PtrReplacer when select has mismatch AS. (PR #98456)

[Matt Arsenault via llvm-commits]

https://github.com/arsenm commented:

Checking specifically for select x, cast, cast seems too specific of a pattern to defend against an assertion. What happens if there are arbitrary indexing separating them? 

https://github.com/llvm/llvm-project/pull/98456