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

sdk/lib/_internal/pub_generated/test/dart2js/includes_source_maps_in_debug_test.dart

Index: sdk/lib/_internal/pub_generated/test/dart2js/includes_source_maps_in_debug_test.dart
diff --git a/sdk/lib/_internal/pub_generated/test/dart2js/includes_source_maps_in_debug_test.dart b/sdk/lib/_internal/pub_generated/test/dart2js/includes_source_maps_in_debug_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..4e5d9e8d467760b025cbca622e6d1aa8fd4a6511
--- /dev/null
+++ b/sdk/lib/_internal/pub_generated/test/dart2js/includes_source_maps_in_debug_test.dart
@@ -0,0 +1,40 @@
+// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS d.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("includes source map URLs in a debug build", () {
+    d.dir(
+        appPath,
+        [
+            d.appPubspec(),
+            d.dir(
+                "web",
+                [d.file("main.dart", "void main() => print('hello');")])]).create();
+
+    schedulePub(
+        args: ["build", "--mode", "debug"],
+        output: new RegExp(r'Built \d+ files to "build".'),
+        exitCode: 0);
+
+    d.dir(
+        appPath,
+        [
+            d.dir(
+                'build',
+                [
+                    d.dir(
+                        'web',
+                        [
+                            d.matcherFile('main.dart.js', contains("# sourceMappingURL=main.dart.js.map")),
+                            d.matcherFile(
+                                'main.dart.js.map',
+                                contains('"file": "main.dart.js"'))])])]).validate();
+  });
+}