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

sdk/lib/_internal/pub_generated/test/transformer/loads_different_configurations_from_the_same_isolate_test.dart

+library pub_tests;
+import '../descriptor.dart' as d;
+import '../test_pub.dart';
+import '../serve/utils.dart';
+main() {
+  initConfig();
+  withBarbackVersions("any", () {
+    integration("loads different configurations from the same isolate", () {
+      d.dir("foo", [d.pubspec({
+          "name": "foo",
+          "version": "1.0.0",
+          "transformers": [{
+              "foo/first": {
+                "addition": " in foo"
+              }
+            }, "foo/second"]
+        }),
+            d.dir(
+                "lib",
+                [
+                    d.file("first.dart", dartTransformer('foo/first')),
+                    d.file("second.dart", dartTransformer('foo/second'))])]).create();
+      d.dir(appPath, [d.pubspec({
+          "name": "myapp",
+          "transformers": [{
+              "foo/first": {
+                "addition": " in myapp",
+                "\$include": "web/first.dart"
+              }
+            }, {
+              "foo/second": {
+                "\$include": "web/second.dart"
+              }
+            }],
+          "dependencies": {
+            'foo': {
+              'path': '../foo'
+            }
+          }
+        }),
+            d.dir(
+                "web",
+                [
+                    d.file("first.dart", 'const TOKEN = "myapp/first";'),
+                    d.file("second.dart", 'const TOKEN = "myapp/second";')])]).create();
+      createLockFile('myapp', sandbox: ['foo'], pkg: ['barback']);
+      pubServe();
+      requestShouldSucceed(
+          "first.dart",
+          'const TOKEN = "(myapp/first, foo/first in myapp)";');
+      requestShouldSucceed(
+          "second.dart",
+          'const TOKEN = "(myapp/second, (foo/second, foo/first in foo))";');
+      endPubServe();
+    });
+  });
+}