Add 'self_check' runtime for running self-checking unit tests

pkg/kernel/test/round_trip_test_disabled.dart

Index: pkg/kernel/test/round_trip_test_disabled.dart
diff --git a/pkg/kernel/test/round_trip_test_disabled.dart b/pkg/kernel/test/round_trip_test_disabled.dart
deleted file mode 100644
index 946f25232e339a5690f2e48285908258df206f77..0000000000000000000000000000000000000000
--- a/pkg/kernel/test/round_trip_test_disabled.dart
+++ /dev/null
@@ -1,19 +0,0 @@
-// Copyright (c) 2016, 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.
-library kernel.round_trip_test;
-
-import 'package:test/test.dart';
-import 'round_trip.dart' as cmd;
-
-void main() {
-  test('dart2js', () {
-    cmd.main(['test/data/dart2js.dill']);
-  });
-  test('dart2js-strong', () {
-    cmd.main(['test/data/dart2js-strong.dill']);
-  });
-  test('boms', () {
-    cmd.main(['test/data/boms.dill']);
-  });
-}