[clang] [clang][RISCV] Reorder sema check for RVV type (PR #83553)

[Brandon Wu via cfe-commits]

4vtomat wrote:

Maybe we can modify the current test case, it would get the error message "RISC-V type 'vfloat64m1_t' ... requires the 'zve64x' extension", but should be 'zve64d' instead.

https://github.com/llvm/llvm-project/pull/83553