bug#41570: 26.3; dired chown

[Eli Zaretskii]

> From: Richard Stallman <rms@gnu.org>
> Cc: stefan@marxist.se, 41570@debbugs.gnu.org, blicher@comcast.net
> Date: Sat, 05 Sep 2020 23:54:25 -0400
> 
>   > >   Changing a file's owner not supported on this OS.  Switch to 
> GNU/Linux.
> 
>   > But this is not true: if one has a 'chown' command available (and I
>   > do), it will and should work as intended.
> 
> I was replying to a message which seemed to say there was none, but I
> don't claim to know anything about Windows.

There are ports of GNU Coreutils floating around.

> Whatever the situation may be, the message could give users suitable
> advice.  "Install the chown command to make this work" could be used,
> provided the chown command in question is free software.

If the suggestion is to tweak the text of the error message a little
on non-Posix platforms, it'd be fine by me.  Patches welcome.