Enable some more operator overloading tests, and don't look into an identifier for functions that might not have one

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@59818 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp
index e9d5eb7..2e13352 100644
--- a/lib/AST/Expr.cpp
+++ b/lib/AST/Expr.cpp
@@ -168,6 +168,9 @@
   if (!FDecl)
     return 0;
   
+  if (!FDecl->getIdentifier())
+    return 0;
+
   return FDecl->getIdentifier()->getBuiltinID();
 }