The method has identical implementation for all architectures. Moved it into frames.cc

Drive-by: deleted SafeStackFrameIterator::is_working_iterator_, SafeStackFrameIterator::iteration_done_ is used instead.

BUG=None
R=loislo@chromium.org, svenpanne@chromium.org

Review URL: https://codereview.chromium.org/17581004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15293 ce2b1a6d-e550-0410-aec6-3dcde31c8c00