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

sdk/lib/_internal/pub_generated/test/run/runs_named_app_in_dev_dependency_test.dart

+import '../descriptor.dart' as d;
+import '../test_pub.dart';
+main() {
+  initConfig();
+  integration('runs a named Dart application in a dev dependency', () {
+    d.dir(
+        "foo",
+        [
+            d.libPubspec("foo", "1.0.0"),
+            d.dir("bin", [d.file("bar.dart", "main() => print('foobar');")])]).create();
+    d.dir(appPath, [d.pubspec({
+        "name": "myapp",
+        "dev_dependencies": {
+          "foo": {
+            "path": "../foo"
+          }
+        }
+      })]).create();
+    pubGet();
+    var pub = pubRun(args: ["foo:bar"]);
+    pub.stdout.expect("foobar");
+    pub.shouldExit();
+  });
+}