bug#9402: list-colors-display

[Juri Linkov]

> Done in revision 105619 on the trunk.

Thank you.  I confirm that it's fixed now.

As for platform-specific colors, what I meant is implementing exactly
the same handling of colors as currently is already implemented in Emacs
on Windows where `M-x list-colors-display' lists platform-specific colors
at the end of the color list: `SystemBackground', `SystemWindow',
`SystemWindowText' and all other system colors, and the user can select
system colors in `customize-face' via completion or the "Choose" button
that includes all platform-specific colors.

Another question is why the face definition of `region' has
platform-specific colors for GTK and NS, but not for Windows.
In Emacs on Windows two system colors are available exactly
for that purpose.  Their names are `SystemHilight' (background)
and `SystemHilightText' (foreground).