Don't require help-fns when not needed

* lisp/emacs-lisp/autoload.el, lisp/emacs-lisp/advice.el:
* lisp/emacs-lisp/elint.el:
Don't require help-fns at the top level.
* lisp/emacs-lisp/advice.el (ad-arglist):
* lisp/emacs-lisp/cl-macs.el (cl--transform-lambda):
Don't require help-fns.  (Bug#17001)

lisp/emacs-lisp/advice.el

@@ -2149,7 +2149,6 @@ the cache-id will clear the cache."
 
 (defun ad-arglist (definition)
   "Return the argument list of DEFINITION."
-  (require 'help-fns)
   (help-function-arglist
    (if (or (macrop definition) (ad-advice-p definition))
        (cdr definition)
@@ -2474,8 +2473,6 @@ Example: `(ad-map-arglists '(a &rest args) '(w x y z))' will return
 		       (capitalize (symbol-name class))
 		       (ad-advice-name advice)))))))
 
-(require 'help-fns)	    ;For help-split-fundoc and help-add-fundoc-usage.
-
 (defun ad--make-advised-docstring (function &optional style)
   "Construct a documentation string for the advised FUNCTION.
 Concatenate the original documentation with the documentation

lisp/emacs-lisp/autoload.el

@@ -32,7 +32,6 @@
 
 (require 'lisp-mode)			;for `doc-string-elt' properties.
 (require 'lisp-mnt)
-(require 'help-fns)			;for help-add-fundoc-usage.
 (eval-when-compile (require 'cl-lib))
 
 (defvar generated-autoload-file nil

lisp/emacs-lisp/cl-macs.el

@@ -294,7 +294,6 @@ FORM is of the form (ARGS . BODY)."
                       ;; apparently harmless computation, so it should not
                       ;; touch the match-data.
                       (save-match-data
-                        (require 'help-fns)
                         (cons (help-add-fundoc-usage
                                (if (stringp (car header)) (pop header))
                                ;; Be careful with make-symbol and (back)quote,

lisp/emacs-lisp/elint.el

@@ -46,8 +46,6 @@
 
 ;;; Code:
 
-(require 'help-fns)
-
 (defgroup elint nil
   "Linting for Emacs Lisp."
   :prefix "elint-"