[llvm] Revert "LangRef: Clarify llvm.minnum and llvm.maxnum about sNaN and signed zero (#112852)" (PR #138451)

[Florian Hahn via llvm-commits]

https://github.com/fhahn commented:

> Yes, currently it is not consistent between architectures, and I am working to fix them. Since we cannot implement them in a single so huge patch, we need update the docs and then the code.

I might be missing something, but wouldn't it be an option to first add the new intrinsics, then work on fixing codegen  for them on the major targets and then update LangRef for `maxnum/minnum` and change Clang's `fmax/fmin` to use the new intrinsics?

https://github.com/llvm/llvm-project/pull/138451