[llvm] [SimplifyCFG] handle monotonic wrapped case for D150943 (PR #65882)

[Nikita Popov via llvm-commits]

nikic wrote:

@djkoloski Backports still follow the process at https://llvm.org/docs/GitHub.html#backporting-fixes-to-the-release-branches.

https://github.com/llvm/llvm-project/pull/65882