[llvm] [MachinePipeliner] Improve loop carried dependence analysis (PR #94185)

[Yuta Mukai via llvm-commits]

ytmukai wrote:

@quic-santdas I do not have performance data as I do not have a measurement environment. There are few loops that are no longer pipelined, as shown in the table above, so I consider it more important to fix missed optimizations.

https://github.com/llvm/llvm-project/pull/94185