Happily, this fixes WIN64 failures too.

BUG=
R=titzer@chromium.org

Review URL: https://codereview.chromium.org/709033002

Cr-Commit-Position: refs/heads/master@{#25216}
git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@25216 ce2b1a6d-e550-0410-aec6-3dcde31c8c00