[llvm] [RISCV] Improve llvm.reduce.fmaximum/minimum lowering (PR #75484)

[Craig Topper via llvm-commits]

topperc wrote:

Are you sure the FMINIMUM/FMAXIMUM came from the type legalizer? If the vector type is legal, the type legalizer shouldn't touch it. I would expect LegalizeVectorOps or LegalizeDAG to be where it gets broken down. So I think we could use custom lowering instead of a DAG combine.

https://github.com/llvm/llvm-project/pull/75484