Update class and interface cycle tests

tests/language/interface_cycle_test.dart

 // Copyright (c) 2012, 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 fail because of cycles in super interface relationship.
 
-abstract class C implements B {
+class C implements B {}
 
-}
+class A implements B {}
 
-abstract class A implements B {
-
-}
-
-abstract class B implements A {
-
-}
-
-class InterfaceCycleNegativeTest {
-  static testMain() {
-  }
-}
+class B
+  implements A  /// 01: compile-time error
+  implements A  /// 02: compile-time error
+{}
 
 main() {
-  InterfaceCycleNegativeTest.testMain();
+  new C();  /// 01: continued
+  new List<C>();  /// 02: continued
 }