Revert "Ensure that failure to start an isolate all end up in the future."

tests/isolate/isolate_create_error_helper_lib2.dart

Index: tests/isolate/isolate_create_error_helper_lib2.dart
diff --git a/tests/isolate/isolate_create_error_helper_lib2.dart b/tests/isolate/isolate_create_error_helper_lib2.dart
deleted file mode 100644
index b34983348f93e39beed15cfb975859346ce5ad02..0000000000000000000000000000000000000000
--- a/tests/isolate/isolate_create_error_helper_lib2.dart
+++ /dev/null
@@ -1,11 +0,0 @@
-// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-library isolate.create.error_helper2_lib;
-
-// This library has a main method with wrong parameters.
-
-void main(a, b, c) {
-  print("Three required positional parameters: $a, $b, $c");
-}