Use of negated arches for dpkg dependencies

[Robert Millan <zeratul2@wanadoo.es>]

Hi there,

We need to find a consensus on what to do when a package has linux-specific
build dependencies and we want to disable them for non-linux systems.

The general tendency is adding our dpkg arch to the list of _negated_ arches,
e.g: [!hurd-i386 !freebsd-i386 !netbsd-i386].

This will get weird when we have 13 arches or so, and by the time we reach
that we'd have to send a new patch every time we start another port.

So I suggest that we carry that task where it belongs to. Instead of
maintaining a list of non-linux arches, maintain a list of linux arches, e.g:

[alpha amd64 arm hppa i386 ia64 m68k mips mipsel powerpc s390 sh sparc]

Sounds overkill adding 13 arches at this time, but at some point the negated
list will outgrow the standard one, and then it'll look even worse.

-- 
Robert Millan

"[..] but the delight and pride of Aule is in the deed of making, and in the
thing made, and neither in possession nor in his own mastery; wherefore he
gives and hoards not, and is free from care, passing ever on to some new work."

 -- J.R.R.T, Ainulindale (Silmarillion)