[llvm] [MachinePipeliner] Fix loop-carried dependencies analysis (PR #121907)

[via llvm-commits]

aankit-ca wrote:

Thank you @kasuga-fj for the patch. There are other regressions as well. It would be ideal to avoid introducing a new flag for this patch. In my opinion, a correctness patch should not cause regressions in tests that were previously passing without correctness issues. The best approach would be to address the correctness issue without causing any regressions.

https://github.com/llvm/llvm-project/pull/121907