bug#45264: 26.3; `face-remap-set-base' seems to be bugged

[Eli Zaretskii <eliz@gnu.org>]

> Date: Sat, 19 Dec 2020 10:32:16 -0800 (PST)
> From: Drew Adams <drew.adams@oracle.com>
> Cc: 45264@debbugs.gnu.org
> 
> The confusion is from the doc not saying explicitly
> that each element of SPECS is a face spec, and NOT a
> face.

SPECS has no "elements".  SPECS stands for arguments to the function
beyond the 1st arg FACE.  Each such argument is either a face name or
a list of attribute/value pairs.

I changed the doc string to be more clear about that.

> 2. "why you thought the argument could be a list of
> one or more faces?"
> 
> The doc string explicitly says that elements of
> SPECS can be face names:
> 
>   Each list element should be either a face name or...

That's after it says that you should consider SPECS as "forming" a
list of elements.