Add remaining @@toStringTag symbols to builtins

R=dslomov@chromium.org

Review URL: https://codereview.chromium.org/664333003

Patch from Caitlin Potter <caitpotter88@gmail.com>.

Cr-Commit-Position: refs/heads/master@{#24885}
git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24885 ce2b1a6d-e550-0410-aec6-3dcde31c8c00