Use native async/await support in pub.

sdk/lib/_internal/pub_generated/test/cache/add/no_matching_version_test.dart

Index: sdk/lib/_internal/pub_generated/test/cache/add/no_matching_version_test.dart
diff --git a/sdk/lib/_internal/pub_generated/test/cache/add/no_matching_version_test.dart b/sdk/lib/_internal/pub_generated/test/cache/add/no_matching_version_test.dart
deleted file mode 100644
index dba517a00b7e6f7bd9d316280ee72b57f7978865..0000000000000000000000000000000000000000
--- a/sdk/lib/_internal/pub_generated/test/cache/add/no_matching_version_test.dart
+++ /dev/null
@@ -1,22 +0,0 @@
-// 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 pub_tests;
-
-import '../../test_pub.dart';
-
-main() {
-  initConfig();
-  integration('fails if no version matches the version constraint', () {
-    servePackages((builder) {
-      builder.serve("foo", "1.2.2");
-      builder.serve("foo", "1.2.3");
-    });
-
-    schedulePub(
-        args: ["cache", "add", "foo", "-v", ">2.0.0"],
-        error: 'Package foo has no versions that match >2.0.0.',
-        exitCode: 1);
-  });
-}