bug#45438: 27.1; please fix misleading documentation for assoc-delete-all

[Eli Zaretskii <eliz@gnu.org>]

> From: Richard Stallman <rms@gnu.org>
> Date: Sat, 26 Dec 2020 05:28:00 -0500
> Cc: hendrik.tews@kernkonzept.com, 45438@debbugs.gnu.org
> 
> Every new function is listed in the ChangeLog files.
> _We_ know when it was introduced.
> 
> What this means
> 
>   > > assoc-delete-all was introduced in emacs 26.2, however,
>   > > describe-function says "Probably introduced at or before Emacs
>   > > version 21.1.".
> 
> is that the data that describe-function consults does not have all the
> information that we have.

If the suggestion is to use ChangeLog data for this feature, then I
think it won't be easy, because it isn't easy to parse the ChangeLog
text for gleaning this more accurate information.  For starters, we
sometimes say "New function", sometimes just "New", and sometimes have
lists of functions (all of which are new) with a single "New" entry.

It would be better to have a DB of this data, which we would update
with each major release, than to try to parse ChangeLog files, IMO.