bouyer-xenamd64 merge (xen roadmap)

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

Hi,
bouyer-xenamd64 is now in quite good shape: a amd64 domU kernel runs 
stable, and a dom0 kernel boots and can start a domU (I've still a bug to
track down which cause dom0 to panic under paging activity when there are
domUs running , but it shouldn't be too hard to track down).
The remaining item I want to do before merging to HEAD is investigate
whenever it's possible to use the new config(5) ifdef blocks to merge back\
arch/xenamd64/conf to arch/amd64/conf and get rid of arch/xenamd64
entirely. If it's possible some files would have to move, but nothing much
should change in C files.

As I'd like to get this branch merged in HEAD ASAP after looking at this last
item, please start looking at the changes made to x86 and amd64 and complain
now if you find some part unacceptable.

Once bouyer-xenamd64 is merged, I'll start a new branch to work on
switching xeni386 to the new x86 pmap and xenamd64 bootstrap codes, and
merge back code from xen/i386 to i386/i386. I'll also look at x86pae support
in Xen, as using the x86 pmap should make this much easier.

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--