Add file missing from earlier commit.

dart/sdk/bin/dart2js_developer

Index: dart/sdk/bin/dart2js_developer
diff --git a/dart/sdk/bin/dart2js_developer b/dart/sdk/bin/dart2js_developer
new file mode 100644
index 0000000000000000000000000000000000000000..948cb4a0ea5795193227d19cb2900955c4ea5abb
--- /dev/null
+++ b/dart/sdk/bin/dart2js_developer
@@ -0,0 +1,6 @@
+#!/bin/bash
+# Copyright (c) 2012, 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.
+
+. ${BASH_SOURCE%_developer}