[RFC] document Cygwin native specific commands

[Andrew Cagney]

> 
> The GDB manual uses @kindex to put all the GDB commands into a
> separate index, while @cindex entries go into the Concept Index.
> Right now, this line near the beginning of gdb.texinfo:
> 
>     @syncodeindex ky cp
> 
> causes the @kindex entries to be printed together with the @cindex
> entries.  But it is enough to remove that line to cause them to be in
> 2 different indices.

Hmm.  Given a dump of all of GDB's commands, should there be a kindex 
for each?  What about the reverse?

I think we might have just stumbled across something that is feasible 
for the ARI to check.

enjoy,
Andrew