Use native async/await support in pub.

sdk/lib/_internal/pub_generated/test/validator/dependency_override_test.dart

Index: sdk/lib/_internal/pub_generated/test/validator/dependency_override_test.dart
diff --git a/sdk/lib/_internal/pub_generated/test/validator/dependency_override_test.dart b/sdk/lib/_internal/pub_generated/test/validator/dependency_override_test.dart
deleted file mode 100644
index 75a64f7be814dac8100cf774c8770e4f886ac756..0000000000000000000000000000000000000000
--- a/sdk/lib/_internal/pub_generated/test/validator/dependency_override_test.dart
+++ /dev/null
@@ -1,28 +0,0 @@
-// Copyright (c) 2013, 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.
-
-import '../../lib/src/entrypoint.dart';
-import '../../lib/src/validator.dart';
-import '../../lib/src/validator/dependency_override.dart';
-import '../descriptor.dart' as d;
-import '../test_pub.dart';
-import 'utils.dart';
-
-Validator dependencyOverride(Entrypoint entrypoint) =>
-    new DependencyOverrideValidator(entrypoint);
-
-main() {
-  initConfig();
-
-  integration('invalidates a package if it has dependency overrides', () {
-    d.dir(appPath, [d.pubspec({
-        "name": "myapp",
-        "dependency_overrides": {
-          "foo": "<3.0.0"
-        }
-      })]).create();
-
-    expectValidationError(dependencyOverride);
-  });
-}