Use package:test_reflective_loader instead of reflective_tests.

pkg/analysis_server/test/integration/asynchrony_test.dart

Index: pkg/analysis_server/test/integration/asynchrony_test.dart
diff --git a/pkg/analysis_server/test/integration/asynchrony_test.dart b/pkg/analysis_server/test/integration/asynchrony_test.dart
index 238b586344c3d04d71a4e9fb08a9f6a87832f8c8..79852cb84ba0aa005680ad0e6da9634e6284af52 100644
--- a/pkg/analysis_server/test/integration/asynchrony_test.dart
+++ b/pkg/analysis_server/test/integration/asynchrony_test.dart
@@ -6,13 +6,13 @@ library test.integration.analysis.error;
 
 import 'dart:async';
 
+import 'package:test_reflective_loader/test_reflective_loader.dart';
 import 'package:unittest/unittest.dart';
 
-import '../reflective_tests.dart';
 import 'integration_tests.dart';
 
 main() {
-//  runReflectiveTests(AsynchronyIntegrationTest);
+//  defineReflectiveTests(AsynchronyIntegrationTest);
 }
 
 /**