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/lib/src/command/list_package_dirs.dart b/sdk/lib/_internal/pub_generated/lib/src/command/list_package_dirs.dart
similarity index 93%
copy from sdk/lib/_internal/pub/lib/src/command/list_package_dirs.dart
copy to sdk/lib/_internal/pub_generated/lib/src/command/list_package_dirs.dart
index 9f6a1e2b00b1493ddbfb24feb86f4fb6d8331f3d..c68d8e0289dcc6f89e887ef513ced7fe06cba95f 100644
--- a/sdk/lib/_internal/pub/lib/src/command/list_package_dirs.dart
+++ b/sdk/lib/_internal/pub_generated/lib/src/command/list_package_dirs.dart
@@ -21,7 +21,8 @@ class ListPackageDirsCommand extends PubCommand {
   bool get hidden => true;
 
   ListPackageDirsCommand() {
-    argParser.addOption("format",
+    argParser.addOption(
+        "format",
         help: "How output should be displayed.",
         allowed: ["json"]);
   }
@@ -52,10 +53,7 @@ class ListPackageDirsCommand extends PubCommand {
 
     // 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
-    ];
+    output["input_files"] = [entrypoint.lockFilePath, entrypoint.pubspecPath];
 
     return Future.wait(futures).then((_) {
       log.json.message(output);