base cygwin patches

[Russ Allbery]

Applied with some twists.

greg andruk <gja at meowing.net> writes:

> Configure goo for cygwin:
>  - make <arpa/nameser.h> and <resolv.h> optional for innfeed

These don't appear to be needed at all, so I just deleted them.  I can't
imagine what in there innfeed would have been using.

>  - fixup libperl's name, cygwin's looks like "libperl5_6_1.a"

Applied, with some slight tweaks.  I don't quite understand why this is
needed, though; Perl should really tell us the correct link line for its
libraries.

>  - cygwin's IOV_MAX is 2147483646, which breaks an assumption about
>    array sizes in nnrpd, so force an arbitrary typical size in
>    configure.  Rename to INN_IOV_MAX to avoid #undef/#define confusion

I took another route with this.  The uses in innfeed were safe, so in
nnrpd where IOV_MAX was used to declare arrays, I just capped it at 1024.
Thankfully ?: operators are allowed in integer constant expressions.

Thanks!

-- 
Russ Allbery (rra at stanford.edu)             <http://www.eyrie.org/~eagle/>