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

[Nikita Popov via llvm-commits]

https://github.com/nikic requested changes to this pull request.

This optimization looks invalid to me. The claim you're making here is essentially this? https://alive2.llvm.org/ce/z/vzy3qB

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