[llvm] Reland [llvm] Add support for llvm IR atomicrmw fminimum/fmaximum instructions (PR #137701)

[Pierre van Houtryve via llvm-commits]

https://github.com/Pierre-vh approved this pull request.

Tablegen test update looks good to me, I didn't look at the rest though

https://github.com/llvm/llvm-project/pull/137701