(frame-parameter): Add a setf method.

(ignore-errors): Don't bother using a `err' symbol.

lisp/emacs-lisp/cl-macs.el

@@ -1587,6 +1587,7 @@ Example: (defsetf nth (n x) (v) (list 'setcar (list 'nthcdr n x) v))."
 (defsetf frame-parameters modify-frame-parameters t)
 (defsetf frame-visible-p cl-set-frame-visible-p)
 (defsetf frame-width set-screen-width t)
+(defsetf frame-parameter set-frame-parameter)
 (defsetf getenv setenv t)
 (defsetf get-register set-register)
 (defsetf global-key-binding global-set-key)
@@ -2313,8 +2314,7 @@ omitted, a default message listing FORM itself is used."
 (defmacro ignore-errors (&rest body)
   "Execute FORMS; if an error occurs, return nil.
 Otherwise, return result of last FORM."
-  (let ((err (gensym)))
-    (list 'condition-case err (cons 'progn body) '(error nil))))
+  `(condition-case nil (progn ,@body) (error nil)))
 
 
 ;;; Some predicates for analyzing Lisp forms.  These are used by various