This fixes 15 leaks, returning 132 bytes of lost memory.

As an additional bonus, elements accessors initialization has bee simplified a bit.

Review URL: https://chromiumcodereview.appspot.com/9836109

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11154 ce2b1a6d-e550-0410-aec6-3dcde31c8c00