[coreboot] [PATCH] Factor out common CAR asm snippets

[Myles Watson]

> IMHO the patch makes it really hard to actually see what the code does.
> I think Idwer was recently running into a problem where the use of
> post_code would trash %eax were hard to comprehend. Now we seem have a
> lot more code that comes from somewhere else and touches registers
> without it being obvious to the reader of the code.

I agree for Save/Restore BIST, since it's only one line.  I like the macros
for longer snippets, though.  Would a comment like 

/* Clobbers %eax, %edx, ... */

be the right way to fix it?  Would it be better to have the clobber list in
the name?

disable_sse_with_eax()?

Thanks,
Myles