Check in a binary of gold from binutils 2.21.1.

This will be used by the Chrome build to make gold the default.
Review URL: https://chromiumcodereview.appspot.com/9302017

git-svn-id: http://src.chromium.org/svn/trunk/deps/third_party/gold@119932 4ff67af0-8c30-449e-8e8b-ad334ec8d88c