sfxge: Remove interrupt self-test code

[Marius Strobl]

On Fri, Nov 18, 2011 at 09:34:11PM +0000, Ben Hutchings wrote:
> sfxge: Remove interrupt self-test code
> 
> It's not currently used; it didn't build on 32-bit and the previous
> build fix is incorrect.  If we really implement self-tests we can do
> this again properly.

Yes, I've also already noticed that this part of r227640 wasn't quite
correct. However Philip suggested to just leave it in for now until
we figure out what on earth the code actually is supposed to do and as
the atomic_cmpset_ptr(9) also works on LP64 and isn't more broken than
the atomic_cmpset_long(9) that was in there before (actually this should
have been atomic_cmpset_64(9) for an uint64_t, which isn't necessarily
available on ILP32 including i386 though). Probably this should have
been converted to be of type cpuset_t and to use the accessors from           
<sys/cpuset.h> as nowadays we also support more than 64 CPUs. I'm also
fine with just nuking the interrupt self-test altogether though.

Marius