[clang] [RISCV] Refactor checkRVVTypeSupport to use BuiltinVectorTypeInfo. (PR #74949)

[Craig Topper via cfe-commits]

topperc wrote:

> Looks good.
> 
> If I understand correctly, you mean that `vbool64_t` should emit diagnosis of requiring `zve64x` and should not emit error of `zve32x.`

Correct. Since vbool64_t requires SEW/LMUL==64 which is only possible with SEW=8 LMUL=1/8, SEW=16 LMUL=1/4 or SEW=32 LMUL=1/2. None of those are valid with Zve32x.

Here's the rvv-intrinsic-doc update that goes with this https://github.com/riscv-non-isa/rvv-intrinsic-doc/pull/302/files

https://github.com/llvm/llvm-project/pull/74949