Fix type tests involving an implicit closure of a non-parameterized class

tests/language/src/MethodOverrideTest.dart

Index: tests/language/src/MethodOverrideTest.dart
===================================================================
--- tests/language/src/MethodOverrideTest.dart	(revision 0)
+++ tests/language/src/MethodOverrideTest.dart	(revision 0)
@@ -0,0 +1,59 @@
+// 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.
+
+// Checks that a method with an instantiated return type can override a method
+// with a generic return type.
+
+typedef Collection<K> GetKeysFunctionType<K>();
+
+class MapBase<K, V> implements Map<K, V> {
+  Collection<K> getKeys() {
+    throw 'Must be implemented';
+  }
+
+  void Tests() {
+    Expect.isTrue(this is MapBase<int, int>);
+
+    Expect.isTrue(getKeys is GetKeysFunctionType);
+    Expect.isTrue(getKeys is GetKeysFunctionType<int>);
+    Expect.isTrue(getKeys is !GetKeysFunctionType<String>);
+    Expect.isTrue(getKeys is !GetKeysFunctionType<MapBase<int, int>>);
+  }
+}
+
+
+class MethodOverrideTest extends MapBase<String, String> {
+  Collection<String> getKeys() {
+    throw 'Is implemented';
+  }
+
+  void Tests() {
+    Expect.isTrue(this is MethodOverrideTest);
+    Expect.isTrue(this is MapBase<String, String>);
+
+    Expect.isTrue(getKeys is GetKeysFunctionType);
+    Expect.isTrue(getKeys is GetKeysFunctionType<String>);
+    Expect.isTrue(getKeys is !GetKeysFunctionType<int>);
+    Expect.isTrue(super.getKeys is GetKeysFunctionType);
+    Expect.isTrue(super.getKeys is GetKeysFunctionType<String>);
+    Expect.isTrue(super.getKeys is !GetKeysFunctionType<int>);
+  }
+}
+
+
+main() {
+  // Since method overriding is only checked statically, explicitly check
+  // the subtyping relation using a function type alias.
+  var x = new MethodOverrideTest();
+  Expect.isTrue(x.getKeys is GetKeysFunctionType<String>);
+
+  // Perform a few more tests.
+  x.Tests();
+
+  var m = new MapBase<int, int>();
+  Expect.isTrue(m.getKeys is GetKeysFunctionType<int>);
+
+  // Perform a few more tests.
+  m.Tests();
+}