[llvm] [NVPTX] instcombine known pointer AS checks. (PR #112964)

[via llvm-commits]

goldsteinn wrote:

AFAICT this is the only target specific handling in InstSimplify which, at least as i understand, we attempt to keep as target independent as possible in a similar way to InstCombine because its for generalized middle end canonicalization.

If there is a need for this sort of change, I think it should be done more similarly to how we do `targetInstCombineIntrinsic` with InstCombine instead ofadding all the target intrinsics directly to the InstructionSimplify file.


https://github.com/llvm/llvm-project/pull/112964