merging bits of [cherry-xenmp]

[Cherry G. Mathew <cherry%zyx.in@localhost>]

Hi,

I'd like to start merging in bits of the cherry-xenmp branch into
-current over the coming week. The changes should be transparent, and
shouldn't change any behaviour of -current. These include a few cleanups
of MD code and some MP related changes (eg: to x86 pmap)  that should be
agnostic to XEN UP, port-i386 and port-amd64. Where relevant, I will
make sure that code is reviewed before committing.


Please let me know in the next couple of days if there are serious
objections to this.

Cheers,

-- 
Cherry

PS: Xen MP support is not intended through these merges.