Avoid redundant calls to "pub list" when multiple dependencies change.

pkg/analysis_server/test/source/test_all.dart

 // Copyright (c) 2015, 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.source;
 
 import 'caching_put_package_map_provider_test.dart' as caching_provider_test;
+import 'optimizing_pub_package_map_provider_test.dart'
+    as optimizing_provider_test;
 import 'package:unittest/unittest.dart';
 
 /// Utility for manually running all tests.
 main() {
   groupSep = ' | ';
   caching_provider_test.main();
+  optimizing_provider_test.main();
 }