[llvm] [InstSimplify] `A == MIN_INT ? B != MIN_INT : A < B` to `A < B` (PR #120177)

[Yingwei Zheng via llvm-commits]

https://github.com/dtcxzyw requested changes to this pull request.

It is incorrect to preserve `samesign` flag: https://alive2.llvm.org/ce/z/2NdTWW

You should either implement this fold and drop the flag in InstCombine or bail out on icmps with `samesign` in InstSimplify.


https://github.com/llvm/llvm-project/pull/120177