dependent, so we push it down to the architecture dependent files.
Currently all architectures visit in almost the same way, but this is
about to change on ARM with movw/movt.
Review URL: http://codereview.chromium.org/2218002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4721 ce2b1a6d-e550-0410-aec6-3dcde31c8c00