Simplify byte-code optimisation of pure functions
Most pure functions need no explicit optimisation; we can do away with almost all uses of byte-optimize-predicate (now renamed to byte-optimize-constant-args, since it is not just for predicates). Also remove some superfluous arity warnings. * lisp/emacs-lisp/byte-opt.el (byte-optimize-identity, byte-optimize-memq) (byte-optimize-nth, byte-optimize-nthcdr): Remove arity warnings and simplify. * lisp/emacs-lisp/byte-opt.el (<, >, <=, >=, not, null, consp, listp) (symbolp, stringp, string<, string-lessp, proper-list-p, logand) (logior, logxor, lognot, car, cdr, car-safe, cdr-safe): Remove superfluous byte-optimizer property. (byte-optimize-predicate): Rename to byte-optimize-constant-args. All uses changed.