[llvm] [InstCombine] fold `sub(zext(ptrtoint), zext(ptrtoint))` (PR #115369)

[Nikita Popov via llvm-commits]

nikic wrote:

I believe you're doing this now, which is still incorrect: https://alive2.llvm.org/ce/z/irt9qk

Both of these variant work though: https://alive2.llvm.org/ce/z/tdpQth (I generalized inbounds -> nusw in the first one.)

https://github.com/llvm/llvm-project/pull/115369