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

sdk/lib/_internal/pub_generated/test/global/activate/installs_dependencies_test.dart

+import 'package:scheduled_test/scheduled_test.dart';
+import '../../test_pub.dart';
+main() {
+  initConfig();
+  integration('activating a package installs its dependencies', () {
+    servePackages((builder) {
+      builder.serve("foo", "1.0.0", deps: {
+        "bar": "any"
+      });
+      builder.serve("bar", "1.0.0", deps: {
+        "baz": "any"
+      });
+      builder.serve("baz", "1.0.0");
+    });
+    schedulePub(
+        args: ["global", "activate", "foo"],
+        output: allOf(
+            [contains("Downloading bar 1.0.0..."), contains("Downloading baz 1.0.0...")]));
+  });
+}