Fix va_arg bug noticed by Eli, __builtin_va_arg is not an l-value
designating an object.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@64371 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp
index 95a6a34..7b06a3c 100644
--- a/lib/AST/Expr.cpp
+++ b/lib/AST/Expr.cpp
@@ -565,7 +565,7 @@
   case PredefinedExprClass:
     return LV_Valid;
   case VAArgExprClass:
-    return LV_Valid;
+    return LV_NotObjectType;
   case CXXDefaultArgExprClass:
     return cast<CXXDefaultArgExpr>(this)->getExpr()->isLvalue(Ctx);
   case CXXConditionDeclExprClass: