Fix/test decltype dtor calls with invalid base expression.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@146354 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaExprCXX.cpp b/lib/Sema/SemaExprCXX.cpp
index af29784..59369d6 100644
--- a/lib/Sema/SemaExprCXX.cpp
+++ b/lib/Sema/SemaExprCXX.cpp
@@ -266,7 +266,7 @@
 }
 
 ParsedType Sema::getDestructorType(const DeclSpec& DS, ParsedType ObjectType) {
-    if (DS.getTypeSpecType() == DeclSpec::TST_error)
+    if (DS.getTypeSpecType() == DeclSpec::TST_error || !ObjectType)
       return ParsedType();
     assert(DS.getTypeSpecType() == DeclSpec::TST_decltype 
            && "only get destructor types from declspecs");