[llvm] [InstCombine] Fold shifts + selects with -1 to scmp(X, 0) (PR #164129)

[Yingwei Zheng via llvm-commits]

https://github.com/dtcxzyw approved this pull request.

Please add some negative tests and provide the alive2 proof.


https://github.com/llvm/llvm-project/pull/164129