bug#14966: 24.3.50; Char-displayable-p is a very long running function

[Eli Zaretskii]

> From: Stefan Kangas <stefan@marxist.se>
> Date: Wed, 18 Nov 2020 07:24:21 -0800
> Cc: Sebastien Vauban <sva-news@mygooglest.com>, 14966@debbugs.gnu.org
> 
> 0. emacs -Q
> 1. (benchmark-run 1 (char-displayable-p ?\u25B7))
> 
> (The above takes 200ms here.)
> 
> Is this something we will want to do something about or is this all
> working as expected?  The discussion in the bug report suggests that
> this is indeed something that we can live with.

I think we can, indeed.