Add missing check for error return from DefaultLvalueConversion.  Fixes <rdar://problem/12857416>.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@170056 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaExprCXX.cpp b/lib/Sema/SemaExprCXX.cpp
index 5345e8d..e3df0a3 100644
--- a/lib/Sema/SemaExprCXX.cpp
+++ b/lib/Sema/SemaExprCXX.cpp
@@ -2026,6 +2026,8 @@
   if (!Ex.get()->isTypeDependent()) {
     // Perform lvalue-to-rvalue cast, if needed.
     Ex = DefaultLvalueConversion(Ex.take());
+    if (Ex.isInvalid())
+      return ExprError();
 
     QualType Type = Ex.get()->getType();