[clang] [RISCV] Verify vfwmaccbf16 and vfncvtbf16 FRM argument in SemaRISCV::CheckBuiltinFunctionCall. (PR #155710)

[Pengcheng Wang via cfe-commits]

https://github.com/wangpc-pp approved this pull request.

LGTM.

Can we add some tests if it doesn't bother you?

https://github.com/llvm/llvm-project/pull/155710