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

sdk/lib/_internal/pub_generated/lib/src/command/list_package_dirs.dart

Index: sdk/lib/_internal/pub_generated/lib/src/command/list_package_dirs.dart
diff --git a/sdk/lib/_internal/pub_generated/lib/src/command/list_package_dirs.dart b/sdk/lib/_internal/pub_generated/lib/src/command/list_package_dirs.dart
deleted file mode 100644
index c68d8e0289dcc6f89e887ef513ced7fe06cba95f..0000000000000000000000000000000000000000
--- a/sdk/lib/_internal/pub_generated/lib/src/command/list_package_dirs.dart
+++ /dev/null
@@ -1,63 +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.
-
-library pub.command.list_package_dirs;
-
-import 'dart:async';
-
-import 'package:path/path.dart' as path;
-
-import '../command.dart';
-import '../log.dart' as log;
-import '../utils.dart';
-
-/// Handles the `list-package-dirs` pub command.
-class ListPackageDirsCommand extends PubCommand {
-  String get name => "list-package-dirs";
-  String get description => "Print local paths to dependencies.";
-  String get invocation => "pub list-package-dirs";
-  bool get takesArguments => false;
-  bool get hidden => true;
-
-  ListPackageDirsCommand() {
-    argParser.addOption(
-        "format",
-        help: "How output should be displayed.",
-        allowed: ["json"]);
-  }
-
-  Future run() {
-    log.json.enabled = true;
-
-    if (!entrypoint.lockFileExists) {
-      dataError('Package "myapp" has no lockfile. Please run "pub get" first.');
-    }
-
-    var output = {};
-
-    // Include the local paths to all locked packages.
-    var packages = {};
-    var futures = [];
-    entrypoint.lockFile.packages.forEach((name, package) {
-      var source = entrypoint.cache.sources[package.source];
-      futures.add(source.getDirectory(package).then((packageDir) {
-        packages[name] = path.join(packageDir, "lib");
-      }));
-    });
-
-    output["packages"] = packages;
-
-    // Include the self link.
-    packages[entrypoint.root.name] = entrypoint.root.path("lib");
-
-    // Include the file(s) which when modified will affect the results. For pub,
-    // that's just the pubspec and lockfile.
-    output["input_files"] = [entrypoint.lockFilePath, entrypoint.pubspecPath];
-
-    return Future.wait(futures).then((_) {
-      log.json.message(output);
-    });
-  }
-}
-