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

[Luke Lau via llvm-commits]

lukel97 wrote:

> #109900 will affect the tests in this patch so one of us will need to rebase.

I don't mind rebasing so feel free to land that first

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