Move cXXXr and cXXXXr to subr.el

Move cXXXr and cXXXXr to subr.el

* etc/NEWS: Mention new core Elisp.
* doc/lispref/lists.texi (List Elements): Document and index the new
functions.
* doc/misc/cl.texi (List Functions): Change "defines" to "aliases".
* lisp/subr.el (caaar, caadr, cadar, caddr, cdaar, cdadr, cddar)
(cdddr, caaaar caaadr, caadar, caaddr, cadaar, cadadr, caddar):
(cadddr, cdaaar, cdaadr, cdadar, cdaddr, cddaar, cddadr, cdddar):
(cddddr): New functions.
* lisp/emacs-lisp/cl-lib.el (cl-caaar, cl-caadr, cl-cadar, cl-caddr):
(cl-cdaar, cl-cdadr, cl-cddar cl-cdddr, cl-caaaar cl-caaadr):
(cl-caadar, cl-caaddr, cl-cadaar, cl-cadadr, cl-caddar, cl-cadddr):
(cl-cdaaar, cl-cdaadr, cl-cdadar, cl-cdaddr, cl-cddaar, cl-cddadr):
(cl-cdddar, cl-cddddr): Alias to new subr functions.
* lisp/emacs-lisp/cl.el (cl-unload-function): Remove cXXXr and cXXXXr
elements.