Split serialization tests further

tests/compiler/dart2js/serialization/model4_test.dart

Index: tests/compiler/dart2js/serialization/model4_test.dart
diff --git a/tests/compiler/dart2js/serialization/model0_test.dart b/tests/compiler/dart2js/serialization/model4_test.dart
similarity index 66%
copy from tests/compiler/dart2js/serialization/model0_test.dart
copy to tests/compiler/dart2js/serialization/model4_test.dart
index 39245e5cdfbe17a65ded0f4635d1f39353a86794..5871fc2206b19b28f96fc02fa304fb1bed4a228f 100644
--- a/tests/compiler/dart2js/serialization/model0_test.dart
+++ b/tests/compiler/dart2js/serialization/model4_test.dart
@@ -2,11 +2,11 @@
 // 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 dart2js.serialization.model0_test;
+library dart2js.serialization.model4_test;
 
 import 'model_test_helper.dart' as test;
-import 'test_data.dart';
+import 'test_helper.dart';
 
 main() {
-  test.main(['0', '0']);
+  test.main(testSegment(4, test.SPLIT_COUNT, test.SKIP_COUNT));
 }