[RFA] win32-nat.c: Simplify generation of Windows environment

[Eli Zaretskii]

> Date: Thu, 7 Dec 2006 10:58:39 +0100
> From: Corinna Vinschen <vinschen@redhat.com>
> 
> the below patch simplifies the code which translates the Cygwin
> environment into the native Windows environment.  So far this is
> done in GDB manually.  However, there's a Cygwin specific function
> call which does the same for the calling process.  Using this call
> has three advantages.

Is win32-nat.c used only for the Cygwin build?  I thought the native
Windows build used it as well (perhaps with a few patches that are not
yet part of the CVS), but maybe I was mistaken.

If I am right, then please make this change, and especially the call
to cygwin_internal, conditioned on __CYGWIN__, or some other
Cygwin-specific symbol.