This is part 3 of the mm subsystem overhaul.
The allocator doesn't rely on mutexes anymore and
uses individual per-order spinlocks instead.
Also, it is aware of multiple memory zones (normal
and DMA) as well as emergency reserves.
Page bitmaps take up 50 % less overhead now.
As of now, everything except the code imported
from FreeBSD is proprietary. Of course, it won't
be like this for long, only until we have decided
which license we like to use. The rationale is
that releasing everything under a copyleft license
later is always easier than doing so immediately
and then changing it afterwards.
Naturally, any changes made before this commit are
still subject to the terms of the CNPL.
This has been brewing for quite some time now, and
it still is nowhere near finished, but at least it
compiles now. A lot has changed, and it's still
quite messy (i386 is almost certainly broken now,
i haven't even checked)
That's it, nothing major is gonna happen anymore
until i get amd64 support working and deprecate
the entire i386 branch. 32-bit just adds so many
extra complications to memory management that i
don't want to waste any more energy on this
platform which is obsolete anyway.