Add unhandlified versions of Of() and NowOf().

R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/221813002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@20423 ce2b1a6d-e550-0410-aec6-3dcde31c8c00