x86: newb question - how to build everything which deps on x86

[Joe Damato <ice799@gmail.com>]

Hi -

I am working on cleaning up include/asm-x86/desc_defs.h specifically 
replacing the fields a,b with more descriptive fields and including some 
other cleanups for using idts. I have some changes locally but as I was 
working on this I found that I had to make some changes to 
kernel/apm32.c kernel/cpu/common.c vmi and lguest (they all used the ->a 
and ->b fields directly).

There are probably more things in the kernel that depend on x86 and 
might break with my change. Is there some config flag I can flip to 
build all x86 related things? I tried a few patterns with grep, but I 
just want to make sure I don't break anyone's stuff.

Thanks,
Joe