Add mirror tests for generic interfaces. Add base-language test for malbounded interfaces.

tests/language/malbounded_type_cast_test.dart

Index: tests/language/malbounded_type_cast_test.dart
diff --git a/tests/language/malbounded_type_cast_test.dart b/tests/language/malbounded_type_cast_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..9a80fea0917cf7f3c90fa1def0945dc60628a381
--- /dev/null
+++ b/tests/language/malbounded_type_cast_test.dart
@@ -0,0 +1,16 @@
+// Copyright (c) 2013, 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.
+
+import 'package:expect/expect.dart';
+
+class Super<T extends num> {}
+class Malbounded1 implements Super<String> {}  /// 01: static type warning
+class Malbounded2 extends Super<String> {}  /// 02: static type warning
+
+main() {
+  var s = new Super<int>();
+  Expect.throws(() => s as Malbounded1, (e) => e is CastError);  /// 01: continued
+  Expect.throws(() => s as Malbounded2, (e) => e is CastError);  /// 02: continued
+  Expect.throws(() => s as Super<String>, (e) => e is CastError);  /// 03: static type warning, dynamic type error
+}