[llvm] [SelectOpt] Support BinOps with SExt operands. (PR #115879)

[Igor Kirillov via llvm-commits]

igogo-x86 wrote:

Looks good; the only question is whether we want to add it before or after [#115745](https://github.com/llvm/llvm-project/pull/115745) (assuming it gets accepted)

https://github.com/llvm/llvm-project/pull/115879