builtins files. We should always use %_CallFunction for a couple of
reasons: it cannot be overwritten and it does not wrap basic types in
wrapper objects.

Review URL: http://codereview.chromium.org/6349018

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6524 ce2b1a6d-e550-0410-aec6-3dcde31c8c00