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

[Yuta Mukai via llvm-commits]

ytmukai wrote:

This modification may prevent some codes to be pipelined that are currently pipelined. Increasing the number of patterns to be analyzed might mitigate it. Hexagon enables MachinePipeliner by default so I would like to hear comments from its developers. 
@bcahoon Can I ask you about that? Or should I contact someone else?

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