bug#25706: 26.0.50; Slow C file fontification

[Eli Zaretskii]

> Date: Wed, 9 Dec 2020 18:46:55 +0000
> From: Alan Mackenzie <acm@muc.de>
> Cc: Mattias Engdegård <mattiase@acm.org>,
>  Lars Ingebrigtsen <larsi@gnus.org>, 25706@debbugs.gnu.org
> 
> Move point to a line with a large percentage and type RET to expand
> it.  You can repeat this to expand further.  Please expand the lines
> down to where the percentages remaining are around 5% or 6%.  There
> will be quite a lot of lines near the start showing the same large
> percentage.

One can also expand everything with "C-u RET".