[llvm] [LoopIdiom] Use HashRecognize to optimize CRC (PR #143208)

[Ramkumar Ramachandra via llvm-commits]

artagnon wrote:

Thanks for the review, and sorry about the slow response: I'm currently traveling, but should get back to work next week. I will clarify that I put up this draft mainly for results from LLVM Compile Time Tracker/llvm-opt-benchmark: it currently suffers from correctness issues.

https://github.com/llvm/llvm-project/pull/143208