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

pkg/kernel/test/round_trip_self_check.dart

Index: pkg/kernel/test/round_trip_self_check.dart
diff --git a/pkg/kernel/test/round_trip_test_disabled.dart b/pkg/kernel/test/round_trip_self_check.dart
similarity index 52%
rename from pkg/kernel/test/round_trip_test_disabled.dart
rename to pkg/kernel/test/round_trip_self_check.dart
index 946f25232e339a5690f2e48285908258df206f77..a299f2658605d900add98a1ecdf5fea8de1e3b58 100644
--- a/pkg/kernel/test/round_trip_test_disabled.dart
+++ b/pkg/kernel/test/round_trip_self_check.dart
@@ -3,17 +3,11 @@
 // BSD-style license that can be found in the LICENSE file.
 library kernel.round_trip_test;
 
-import 'package:test/test.dart';
+import 'self_check_util.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']);
+void main(List<String> args) {
+  runSelfCheck(args, (String filename) {
+    cmd.main([filename]);
   });
 }