fixup! [Clang] Correct the DeclRefExpr's Type after the initializer gets instantiated

Author: zyn0217

clang/lib/Sema/SemaExpr.cpp

@@ -19856,12 +19856,7 @@ static void DoMarkVarDeclReferenced(
           // The size of an incomplete array type can be updated by
           // instantiating the initializer. The DeclRefExpr's type should be
           // updated accordingly too, or users of it would be confused!
-          //
-          // FIXME: Do we need to recompute the type for all the Decls, as in
-          // BuildDeclarationNameExpr?
-          if (SemaRef.Context.getAsIncompleteArrayType(DRE->getType()) &&
-              !SemaRef.Context.getAsIncompleteArrayType(Var->getType()))
-            DRE->setType(Var->getType());
+          SemaRef.getCompletedType(DRE);
         } else if (auto *ME = dyn_cast_or_null<MemberExpr>(E))
           ME->setMemberDecl(ME->getMemberDecl());
       } else if (FirstInstantiation) {