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

[Eli Zaretskii]

> From: Spencer Baugh <sbaugh@janestreet.com>
> Cc: Eli Zaretskii <eliz@gnu.org>,  64533@debbugs.gnu.org
> Date: Sat, 08 Jul 2023 16:56:29 -0400
> 
> >> +@vindex which-func-display
> >> +  By default, Which Function mode displays the current function name
> >> +using the mode line.  Customize @code{which-func-display} to
> >> +@code{header}, @code{mode}, or @code{both} to use the header line,
> >
> > Or a list of 'header and/or 'mode.
> 
> Oh much better idea, done:

I disagree that it is a better idea.  It makes a tad harder to
customize the variable in Lisp if the user is not familiar enough with
Emacs Lisp.  The Custom interface is also more cumbersome.

So my clear preference is for the previous variant, with separate
symbols.  If 'both' is too vague, we could use 'mode-and-header'
instead.