[llvm] [InstCombine] Fold `(A < B) ^ ((A - B) < 0)` into `ssub.with.overflow` (PR #216590)

[Yingwei Zheng via llvm-commits]

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

A correctness issue was identified by [llvm-hackme](https://github.com/dtcxzyw/llvm-hackme). Please see the [issue comment](https://github.com/llvm/llvm-project/pull/216590#issuecomment-5309130240) for details.

https://github.com/llvm/llvm-project/pull/216590