[llvm] [X86] Recognise VPMADD52L pattern with AVX512IFMA/AVXIFMA (#153787) (PR #156714)

[Hongyu Chen via llvm-commits]

https://github.com/XChy approved this pull request.

LGTM, cheers. Please wait for @RKSimon to confirm.
It would be better if the unoptimized testcases are updated in the first commit. For example, https://github.com/llvm/llvm-project/pull/156847/commits/f4deffa2fb70968adcce213c0a9f16f11d00b756. The diff makes review easier. Just a reminder for the follow-up patches.

https://github.com/llvm/llvm-project/pull/156714