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

sdk/lib/_internal/pub_generated/test/cache/add/already_cached_test.dart

Index: sdk/lib/_internal/pub_generated/test/cache/add/already_cached_test.dart
diff --git a/sdk/lib/_internal/pub/test/cache/add/already_cached_test.dart b/sdk/lib/_internal/pub_generated/test/cache/add/already_cached_test.dart
similarity index 79%
copy from sdk/lib/_internal/pub/test/cache/add/already_cached_test.dart
copy to sdk/lib/_internal/pub_generated/test/cache/add/already_cached_test.dart
index f6aaa921bf4f2c0acb4a869de79fcd2b3093b002..dad15dafa2cb074e28fd2c595b96f816228330d4 100644
--- a/sdk/lib/_internal/pub/test/cache/add/already_cached_test.dart
+++ b/sdk/lib/_internal/pub_generated/test/cache/add/already_cached_test.dart
@@ -15,13 +15,17 @@ main() {
     });
 
     // Run once to put it in the cache.
-    schedulePub(args: ["cache", "add", "foo"],
+    schedulePub(
+        args: ["cache", "add", "foo"],
         output: 'Downloading foo 1.2.3...');
 
     // Should be in the cache now.
-    schedulePub(args: ["cache", "add", "foo"],
+    schedulePub(
+        args: ["cache", "add", "foo"],
         output: 'Already cached foo 1.2.3.');
 
-    d.cacheDir({"foo": "1.2.3"}).validate();
+    d.cacheDir({
+      "foo": "1.2.3"
+    }).validate();
   });
 }