[llvm] Match range check pattern with SExt (PR #118910)

[Yingwei Zheng via llvm-commits]

https://github.com/dtcxzyw commented:

Looks like it also holds for zext: https://alive2.llvm.org/ce/z/vpYSiD

BTW, can you add a proof for `(icmp slt x, 0) | (icmp sgt sext(x), n) --> icmp ugt x, n`?

https://github.com/llvm/llvm-project/pull/118910