bug#57669: 29.0.50; C-n, C-p off under long lines

[Eli Zaretskii]

> From: dick <dick.r.chiang@gmail.com>
> Cc: Eli Zaretskii <eliz@gnu.org>,  57669@debbugs.gnu.org
> Date: Fri, 09 Sep 2022 11:52:00 -0400
> 
> > Commercial Emacs performs much worse
> 
> I dunno.  As of 103caad, Commercial runs through the 100-line test in
> 3s, about the same as GNU with find-file-literally and non-nil
> long-lines-threshold.

I'm aware of your "solution", and it is unacceptable.