[Sema] Fix bug in builtin AS override (llvm#138141)

Fix the logic in rewriteBuiltinFunctionDecl to work when the builtin
has a pointer parameter with an address space and one without a fixed
address space. A builtin fitting these criteria was recently added.
Change the attribute string to perform type checking on it, so without
the sema change compilation would fail with a wrong number of arguments
error.

Author: Sisyph

clang/lib/Sema/SemaExpr.cpp

@@ -6247,7 +6247,8 @@ static FunctionDecl *rewriteBuiltinFunctionDecl(Sema *Sema, ASTContext &Context,
       return nullptr;
     Expr *Arg = ArgRes.get();
     QualType ArgType = Arg->getType();
-    if (!ParamType->isPointerType() || ParamType.hasAddressSpace() ||
+    if (!ParamType->isPointerType() ||
+        ParamType->getPointeeType().hasAddressSpace() ||
         !ArgType->isPointerType() ||
         !ArgType->getPointeeType().hasAddressSpace() ||
         isPtrSizeAddressSpace(ArgType->getPointeeType().getAddressSpace())) {
@@ -6256,9 +6257,6 @@ static FunctionDecl *rewriteBuiltinFunctionDecl(Sema *Sema, ASTContext &Context,
     }
 
     QualType PointeeType = ParamType->getPointeeType();
-    if (PointeeType.hasAddressSpace())
-      continue;
-
     NeedsNewDecl = true;
     LangAS AS = ArgType->getPointeeType().getAddressSpace();