Check for cyclicity in named mixin applications.

tests/language/mixin_cyclic_test.dart

+// 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.
+
+// Test for cyclicity check on named mixin applications.
+
+class A<T> {}
+
+class S {}
+class M<T> {}
+
+typedef C1 = S with M;
+typedef C2 = S with C2; /// 01: compile-time error
+typedef C3 = S with M implements A;
+typedef C4 = S with M implements C4; /// 02: compile-time error
+
+void main() {
+  new C1();
+  new C2(); /// 01: continued
+  new C3();
+  new C4(); /// 02: continued
+}