[mlir][vector] Bring back `maxf`/`minf` reductions
This patch is part of a larger initiative aimed at fixing floating-point `max` and `min` operations in MLIR: https://discourse.llvm.org/t/rfc-fix-floating-point-max-and-min-operations-in-mlir/72671.
In line with the mentioned RFC, this patch tackles tasks 2.3 and 2.4.
It adds LLVM conversions for the `maxf`/`minf` reductions to the non-NaN-propagating LLVM intrinsics.
Depends on
D158618
Reviewed By: dcaballe
Differential Revision: https://reviews.llvm.org/
D158659