Add xdr support

[Charles Wilson]

Corinna Vinschen wrote:
> Thank you!  Everything's applied.  I just trimmed the ChangeLog entry
> slighty.

Thanks.

I've found a (small) problem though.  I was trying to compile the
(external) tirpc library, and discovered that we need to export two
additional "private" functions from XDR:

__xdrrec_getrec
__xdrrec_setnonblock

There's nothing really "private" about them, but they are not declared
in the xdr.h header -- the libtirpc's rpc implementation declares the
functions itself, but expects them to be provided by XDR.  The newlib
XDR implementation provides them, but I just didn't include them in
cygwin.din.

I'm testing a patch now; will post later.

--
Chuck