[llvm] Intrinsic: introduce minimumnum and maximumnum for IR and SelectionDAG (PR #96649)

[via llvm-commits]

Urgau wrote:

I don't know much about LLVM but why is it introducing new intrinsic while `llvm.minimum.*` and `llvm.maximum.*` already claim to follow the "IEEE 754-2019" definition and has already support in a few backends?

> If either operand is a NaN, returns NaN. Otherwise returns the greater of the two arguments. -0.0 is considered to be less than +0.0 for this intrinsic. Note that these are the semantics specified in the draft of IEEE 754-2019.

https://github.com/llvm/llvm-project/pull/96649