Followup to a recent change in menu-bar.el

* lisp/fileloop.el (fileloop--operate-function): Mention in a
comment that menu-bar.el relies on the default value.

lisp/fileloop.el

@@ -55,6 +55,9 @@
 (defvar fileloop--iterator iter-empty)
 (defvar fileloop--scan-function
   (lambda () (user-error "No operation in progress")))
+;; If the default value below is changed, the :enable form of
+;; tags-continue and tags-repl-continue in menu-bar.el will have to be
+;; updated accordingly.
 (defvar fileloop--operate-function #'ignore)
 (defvar fileloop--freshly-initialized nil)