Bus layer cleanups

[Matt Turner]

ajax sent the original series out in Sept 2010 and has added some
more on top of it since then.

His original message was

On Sep 21, 2010, at 6:28 PM, Adam Jackson wrote:
> This attempts to tackle Tiago's (justified) hatred for the IOADDRESS type
> in a slightly more elegant way.  We move more of the VGA hacks to vgahw,
> port it and int10 over to pciaccess' legacy I/O API, and then clean up
> some of the remaining detritus.
>
> THIS IS AN ABI BREAK.  Like, a pretty massive one.  Please do not pull
> this yet.  I'm mostly looking for r-b's here that the strategy looks
> sane.  The driver work needs to land before this lands, and it's pretty
> trivial, but I don't want to bother unless this is actually going to
> merge.
>
> Once (if) this lands, the only remaining direct usage of {in,out}[bwl]
> in xserver will be xf86SlowBcopy (jokes).  This also makes it plausible
> to convert the rest of the drivers to the pciaccess API, which then
> means we can drop roughly 137% of the content of compiler.h.
>
> ---
>
> The following changes since commit c768cdda92696b636c10bb2df64167d5274b4b99:
>
>  Merge remote branch 'jamey/reviewed' (2010-09-13 16:48:33 -0700)
>
> are available in the git repository at:
>
>  ssh://people.freedesktop.org/~ajax/xserver.git ioaddress

I merged patches 6 and 12 from the ioaddress branch since #12 just added a
lost } from #6. Patch 2 had some tab/space mess which I also fixed.

Let's get this reviewed so we can kill compiler.h.

Thanks,
Matt