New target: x86_64-pc-cygwin

[Joel Brobecker]

Hi Corinna,

> 	* configure.host: Add x86_64-*-cygwin* as host.
> 	* configure.tgt: Add x86_64-*-cygwin* as target.
> 	* config/i386/cygwin64.mh: New file.

This part looks good to me, so please go ahead and commit.

> 	* gdbserver/configure.srv: Add x86_64-*-cygwin* as target.

[gdbserver has its own ChangeLog]

This parts looks good to me, but should probably be reviewed by Pedro
as well.

> Index: gdbserver/configure.srv
> ===================================================================
> RCS file: /cvs/src/src/gdb/gdbserver/configure.srv,v
> retrieving revision 1.72
> diff -u -p -r1.72 configure.srv
> --- gdbserver/configure.srv	27 Feb 2013 14:58:18 -0000	1.72
> +++ gdbserver/configure.srv	5 Mar 2013 11:58:56 -0000
> @@ -326,6 +326,10 @@ case "${target}" in
>  			srv_xmlfiles="$srv_i386_xmlfiles $srv_amd64_xmlfiles"
>  			srv_mingw=yes
>  			;;
> +  x86_64-*-cygwin*)	srv_regobj="$srv_amd64_regobj"
> +			srv_tgtobj="i386-low.o i387-fp.o win32-low.o win32-i386-low.o"
> +			srv_xmlfiles="$srv_i386_xmlfiles"
> +			;;
>  
>    xtensa*-*-linux*)	srv_regobj=reg-xtensa.o
>  			srv_tgtobj="linux-low.o linux-osdata.o linux-xtensa-low.o linux-procfs.o"

-- 
Joel