Switch analysis_server to use 'package:test'.

pkg/analysis_server/test/src/utilities/test_all.dart

 // Copyright (c) 2014, 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 test.services;
 
+import 'package:test_reflective_loader/test_reflective_loader.dart';
+
 import '../../utils.dart';
 import 'change_builder_core_test.dart' as change_builder_core_test;
 import 'change_builder_dart_test.dart' as change_builder_dart_test;
 
 /// Utility for manually running all tests.
 main() {
   initializeTestEnvironment();
-  change_builder_core_test.main();
-  change_builder_dart_test.main();
+  defineReflectiveSuite(() {
+    change_builder_core_test.main();
+    change_builder_dart_test.main();
+  });
 }