[llvm] [RISCV] Lower memory ops and VP splat for zvfhmin and zvfbfmin (PR #109387)

[Craig Topper via llvm-commits]

https://github.com/topperc approved this pull request.

LGTM other than using ZFMIN instead of ZFHMIN in the check-prefixes

https://github.com/llvm/llvm-project/pull/109387