[llvm] [BasicAA] Use nuw attribute of GEPs (PR #98608)

[Nikita Popov via llvm-commits]

nikic wrote:

By the way, I put up https://github.com/llvm/llvm-project/pull/102141 as a complement to this, which handles the simpler case where you have both nusw and nuw (or inbounds and nuw). I think many use cases will be covered by that one, but handling for the "nuw only" case is still desirable, it's just trickier.

https://github.com/llvm/llvm-project/pull/98608