bug#64735: 29.0.92; find invocations are ~15x slower because of ignores

[Eli Zaretskii]

> From: Spencer Baugh <sbaugh@janestreet.com>
> Cc: Michael Albinus <michael.albinus@gmx.de>,  dmitry@gutov.dev,
>    yantar92@posteo.net,  64735@debbugs.gnu.org, Richard Stallman
>   <rms@gnu.org>
> Date: Fri, 21 Jul 2023 15:33:13 -0400
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> > The first idea that comes to mind is to reimplement
> > directory-files-recursively in C, modeled on how Find does that.
> 
> If someone was thinking of doing that, they would be better off
> responding to RMS's earlier request for C programmers to optimize this
> behavior in find.

No, the first step is to use in Emacs what Find does today, because it
will already be a significant speedup.  Optimizing the case of a long
list of omissions should come later, as it is a minor optimization.