[RISCV] Use RISCVV_BUILTIN for vector intrinsic checking.

[HsiangKai]

Summary

There may be other BUILTINs for other extensions. Use RISCVV_BUILTIN for
vector builtin checking.

[craig.topper]

LGTM

clang/lib/Sema/SemaChecking.cpp

 }
 
 bool Sema::CheckRISCVBuiltinFunctionCall(const TargetInfo &TI,
                                          unsigned BuiltinID,
                                          CallExpr *TheCall) {
   switch (BuiltinID) {
   default:
     break;
-#define BUILTIN(ID, TYPE, ATTRS) case RISCV::BI##ID:
+#define RISCVV_BUILTIN(ID, TYPE, ATTRS) case RISCV::BI##ID:
 #include "clang/Basic/BuiltinsRISCV.def"
     if (!TI.hasFeature("experimental-v"))
       return Diag(TheCall->getBeginLoc(), diag::err_riscvv_builtin_requires_v)
              << TheCall->getSourceRange();
     break;
   }
 
   return false;