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

sdk/lib/_internal/pub_generated/test/get/hosted/unlock_if_new_is_unsatisfied_test.dart

+// Copyright (c) 2012, 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 '../../descriptor.dart' as d;
+import '../../test_pub.dart';
+
+main() {
+  initConfig();
+  integration(
+      "unlocks dependencies if necessary to ensure that a new "
+          "dependency is satisfied",
+      () {
+    servePackages((builder) {
+      builder.serve("foo", "1.0.0", deps: {
+        "bar": "<2.0.0"
+      });
+      builder.serve("bar", "1.0.0", deps: {
+        "baz": "<2.0.0"
+      });
+      builder.serve("baz", "1.0.0", deps: {
+        "qux": "<2.0.0"
+      });
+      builder.serve("qux", "1.0.0");
+    });
+
+    d.appDir({
+      "foo": "any"
+    }).create();
+
+    pubGet();
+
+    d.packagesDir({
+      "foo": "1.0.0",
+      "bar": "1.0.0",
+      "baz": "1.0.0",
+      "qux": "1.0.0"
+    }).validate();
+
+    servePackages((builder) {
+      builder.serve("foo", "2.0.0", deps: {
+        "bar": "<3.0.0"
+      });
+      builder.serve("bar", "2.0.0", deps: {
+        "baz": "<3.0.0"
+      });
+      builder.serve("baz", "2.0.0", deps: {
+        "qux": "<3.0.0"
+      });
+      builder.serve("qux", "2.0.0");
+      builder.serve("newdep", "2.0.0", deps: {
+        "baz": ">=1.5.0"
+      });
+    });
+
+    d.appDir({
+      "foo": "any",
+      "newdep": "any"
+    }).create();
+
+    pubGet();
+
+    d.packagesDir({
+      "foo": "2.0.0",
+      "bar": "2.0.0",
+      "baz": "2.0.0",
+      "qux": "1.0.0",
+      "newdep": "2.0.0"
+    }).validate();
+  });
+}