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

sdk/lib/_internal/pub_generated/test/get/path/empty_pubspec_test.dart

+import 'package:path/path.dart' as p;
+import '../../../lib/src/exit_codes.dart' as exit_codes;
+import '../../descriptor.dart' as d;
+import '../../test_pub.dart';
+main() {
+  initConfig();
+  integration('path dependency to an empty pubspec', () {
+    d.dir('foo', [d.libDir('foo'), d.file('pubspec.yaml', '')]).create();
+    d.dir(appPath, [d.appPubspec({
+        "foo": {
+          "path": "../foo"
+        }
+      })]).create();
+    pubGet(
+        exitCode: exit_codes.DATA,
+        error: 'Error on line 1, column 1 of ${p.join('..', 'foo', 'pubspec.yaml')}: '
+            'Missing the required "name" field.');
+  });
+}