bug#14645: Keep highlighting face foreground

[Eli Zaretskii]

> From: Juri Linkov <juri@jurta.org>
> Date: Fri, 14 Aug 2020 02:44:43 +0300
> Cc: 14645@debbugs.gnu.org
> 
> > This hadn't been fixed, so I applied your patch to Emacs 28.
> 
> This patch breaks Info fontification, please revert it.

> Here is what I said in the message sent later with another patch at
> https://debbugs.gnu.org/14645#14
> 
>   Using the text property `face' instead of `font-lock-face'
>   might break something, so a better patch below removes
>   the text properties `face info-index-match' from the Info buffer

Thanks for alerting us to the breakage, but would it be possible to
have a test which would make sure the fontification functionality in
Info is not broken, so that we don't have to rely on the memory and
attention of those who are experts on that?