Yet another unnecessary ElementX reference

tests/compiler/dart2js/serialization/test_data.dart

Index: tests/compiler/dart2js/serialization/test_data.dart
diff --git a/tests/compiler/dart2js/serialization/test_data.dart b/tests/compiler/dart2js/serialization/test_data.dart
index 2924e8e4cb99f96bae2d950abab27c23301b662d..62126fd64173bc14a08cc4a79e1054caec682ba2 100644
--- a/tests/compiler/dart2js/serialization/test_data.dart
+++ b/tests/compiler/dart2js/serialization/test_data.dart
@@ -253,6 +253,17 @@ var myIdentical = identical;
 main() => myIdentical;
 ''',
   }),
+
+  const Test(const {
+    'main.dart': '''
+class Foo {
+  String toString() => super.toString();
+}
+main() {
+  print(new Foo());
+}
+''',
+  }),
 ];
 
 class Test {