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

[via llvm-commits]

aankit-ca wrote:

> Hi @aankit-ca . Let me ask you one question. If there is another patch, would it be possible for you to evaluate its impact on the benchmark as you did before? If so, I would like to try a different approach that (I believe) would reduce regression than this patch. Thanks.

Yes @kasuga-fj we can try benchmarking again on other patches too

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