[llvm] [RISCV][GISel] Add ZFA FP legalization and full tests for 9 insn (PR #118723)

[Min-Yih Hsu via llvm-commits]

================

----------------
mshockwave wrote:

please test legalizer with MIR tests, just like other tests in the same folder

https://github.com/llvm/llvm-project/pull/118723