As far as I can tell from looking through history and searching my source tree we've never had a macro called ASSERT_UNREACHED(). Instead, we have ASSERT_NOT_REACHED(). We should update assertion-guidelines.html to reflect this.
Created attachment 118223 [details] Patch
Comment on attachment 118223 [details] Patch Clearing flags on attachment: 118223 Committed r102248: <http://trac.webkit.org/changeset/102248>
All reviewed patches have been landed. Closing bug.