[llvm] [InstCombine] Support gep nuw in icmp folds (PR #118472)

[Alexander Kornienko via llvm-commits]

alexfh wrote:

That's definitely not the only patch in this area. [e21ab4d16b555c28ded307571d138f594f33e325](https://github.com/llvm/llvm-project/commit/e21ab4d16b555c28ded307571d138f594f33e325) discovers more cases of pointer arithmetic-related UB.

https://github.com/llvm/llvm-project/pull/118472