Revert "Use native async/await support in pub."

sdk/lib/_internal/pub_generated/test/global/activate/removes_old_lockfile_test.dart

Index: sdk/lib/_internal/pub_generated/test/global/activate/removes_old_lockfile_test.dart
diff --git a/sdk/lib/_internal/pub_generated/test/global/activate/removes_old_lockfile_test.dart b/sdk/lib/_internal/pub_generated/test/global/activate/removes_old_lockfile_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..a9ff5c927d7dce8d160497307e14e2024d782662
--- /dev/null
+++ b/sdk/lib/_internal/pub_generated/test/global/activate/removes_old_lockfile_test.dart
@@ -0,0 +1,39 @@
+// 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.
+
+import 'package:scheduled_test/scheduled_test.dart';
+
+import '../../descriptor.dart' as d;
+import '../../test_pub.dart';
+
+main() {
+  initConfig();
+  integration('removes the 1.6-style lockfile', () {
+    servePackages((builder) {
+      builder.serve("foo", "1.0.0");
+    });
+
+    d.dir(
+        cachePath,
+        [
+            d.dir(
+                'global_packages',
+                [
+                    d.file(
+                        'foo.lock',
+                        'packages: {foo: {description: foo, source: hosted, '
+                            'version: "1.0.0"}}}')])]).create();
+
+    schedulePub(args: ["global", "activate", "foo"]);
+
+    d.dir(
+        cachePath,
+        [
+            d.dir(
+                'global_packages',
+                [
+                    d.nothing('foo.lock'),
+                    d.dir('foo', [d.matcherFile('pubspec.lock', contains('1.0.0'))])])]).validate();
+  });
+}