Store the async-await compiled pub code directly in the repo.

sdk/lib/_internal/pub_generated/test/serve/native_watch_added_file_test.dart

+library pub_tests;
+import '../descriptor.dart' as d;
+import '../test_pub.dart';
+import 'utils.dart';
+main() {
+  initConfig();
+  integration(
+      "picks up files added after serving started when using the " "native watcher",
+      () {
+    d.dir(
+        appPath,
+        [d.appPubspec(), d.dir("web", [d.file("index.html", "body")])]).create();
+    pubServe(args: ["--no-force-poll"]);
+    waitForBuildSuccess();
+    requestShouldSucceed("index.html", "body");
+    d.dir(appPath, [d.dir("web", [d.file("other.html", "added")])]).create();
+    waitForBuildSuccess();
+    requestShouldSucceed("other.html", "added");
+    endPubServe();
+  });
+}