Enables clean VM shutdown.

runtime/tests/vm/dart/spawn_infinite_loop_test.dart

Index: runtime/tests/vm/dart/spawn_infinite_loop_test.dart
diff --git a/runtime/tests/vm/dart/spawn_infinite_loop_test.dart b/runtime/tests/vm/dart/spawn_infinite_loop_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..cc0fb42d2a6ac0bac2025d903b21b0352fb0e0a8
--- /dev/null
+++ b/runtime/tests/vm/dart/spawn_infinite_loop_test.dart
@@ -0,0 +1,18 @@
+// Copyright (c) 2015, 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.
+
+import 'dart:isolate';
+
+// This test ensures that the VM can kill the spawned isolate during VM
+// shutdown even when the isolate is in an infinite loop and will not finish
+// on its own.
+
+void loop(msg) {
+  while (true) {}
+  throw "Unreachable";
+}
+
+void main() {
+  Isolate.spawn(loop, []);
+}