As Michael mentioned in https://bugs.webkit.org/show_bug.cgi?id=127777#c15 push of rbp is needed. I tested and it seems it works.
Created attachment 222648 [details] Patch
Comment on attachment 222648 [details] Patch r=me, very nice fix!
Comment on attachment 222648 [details] Patch Clearing flags on attachment: 222648 Committed r163080: <http://trac.webkit.org/changeset/163080>
All reviewed patches have been landed. Closing bug.