bug#64652: 28.2; Adding a property bug on Windows 11

[Eli Zaretskii]

> Cc: senkijun@gmail.com, ruijie@netyu.xyz, 64652@debbugs.gnu.org
> Date: Sun, 16 Jul 2023 12:03:05 +0300
> From: Eli Zaretskii <eliz@gnu.org>
> 
> > AFAIU, it then means that any parser/font-lock keywords may fail to
> > fontify case-insensitive keywords that contain "i" in Turkish language
> > environment.
> 
> In general, yes.  And not only in Turkish, there are a couple more
> "problematic" locales we know about.

Btw, where the pattern includes only upper-case letters, a possibly
cheaper solution is to bind case-fold-search to nil instead.