[clang] [llvm] Intrinsic: introduce minimumnum and maximumnum (PR #93841)

[Matt Arsenault via cfe-commits]

https://github.com/arsenm commented:

> 3. PowerPC: has some interaction with the behavior of `minnum/maxnum`: need define `fcanonicalize`.

AMDGPU has the same handling. This is to break the signaling nan handling from IEEE to the broken old glibc libm behavior. If we fix the definition to match IEEE, this is no longer necessary and the operation is directly legal 

https://github.com/llvm/llvm-project/pull/93841