bug#64533: [PATCH] Support displaying function name in the header line

[Eli Zaretskii]

> From: Spencer Baugh <sbaugh@janestreet.com>
> Date: Sat, 08 Jul 2023 13:56:23 -0400
> 
> +(defcustom which-func-use-header-line nil
> +  "If non-nil, display the function name in the header line."
> +  :type '(choice (const :tag "Display in header line" t)
> +                 (const :tag "Don't display in header line" nil)))
> +
> +(defcustom which-func-use-mode-line t
> +  "If non-nil, display the function name in the mode line."
> +  :type '(choice (const :tag "Display in mode line" t)
> +                 (const :tag "Don't display in mode line" nil)))

Defcustom's should have a :version tag.

And why 2 separate defcustom's instead of just one?  It looks
un-economical, and also allows for situations in which the behavior is
unclear without examining the code.

Also, I think this needs a NEWS entry, and the user manual should be
amended to account for the new optional display.

Thanks.