Use package:test_reflective_loader instead of reflective_tests.

pkg/analysis_server/test/integration/server/shutdown_test.dart

Index: pkg/analysis_server/test/integration/server/shutdown_test.dart
diff --git a/pkg/analysis_server/test/integration/server/shutdown_test.dart b/pkg/analysis_server/test/integration/server/shutdown_test.dart
index 09c4fe414814bb6f69c08aac6403ea83440882dd..7a5de26529f1604100001eca32fcb93afa10840f 100644
--- a/pkg/analysis_server/test/integration/server/shutdown_test.dart
+++ b/pkg/analysis_server/test/integration/server/shutdown_test.dart
@@ -6,13 +6,13 @@ library test.integration.server.shutdown;
 
 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(Test);
+  defineReflectiveTests(Test);
 }
 
 @reflectiveTest