Do not require upper bounds to be resolved and finalized before comparing them

tests/language/src/DefaultFactory3Test.dart

+// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+// Check possibly still unresolved upper bounds of default factory class.
+
+
+interface A<T extends Foo> default _AImpl<T extends Foo> {
+  const A();
+}
+
+class Moo extends Foo {}
+
+class Foo extends Bar {}
+
+class Bar {}
+
+class _AImpl<T extends Foo> implements A<T> {
+   factory _AImpl(){}
+}
+
+main() {
+  var result = new A<Moo>();
+}