Declare caar, cadr, etc. as side-effect-free

Declare caar, cadr, etc. as side-effect-free

* lisp/subr.el (caar, cadr, cdar, cddr, caaar, caadr, cadar, caddr)
(cdaar, cdadr, cddar, cdddr, caaaar, caaadr, caadar, caaddr, cadaar)
(cadadr, caddar, cadddr, cdaaar, cdaadr, cdadar, cdaddr, cddaar)
(cddadr, cdddar, cddddr): Declare side-effect-free.
* lisp/emacs-lisp/cl-macs.el: Remove redundant declarations of
compatibility aliases for the above functions as side-effect-free.

(cherry picked from commit f478d2d1b935f609b6c390c0ef961c00b295bbd7)