bug#38007: scroll-lock binding on Windows

[Eli Zaretskii]

> From: Juanma Barranquero <lekktu@gmail.com>
> Date: Fri, 22 Nov 2019 10:44:55 +0100
> Cc: 38007@debbugs.gnu.org
> 
> AFAICS, the X Window System Protocol 
> (https://www.x.org/releases/X11R7.6/doc/xproto/x11protocol.html)
> defines the keysyms as numeric codes with a conventional name, in this case 
> 
> #xFF14   SCROLL LOCK
> 
> which is represented in /usr/include/X11/keysymdef.h as
> 
> #define XK_Scroll_Lock                   0xff14
> 
> but I don't know how that is converted into a keyboard event.

Yes, the latter is the missing piece.  Maybe put all of the above into
that comment.