[PATCH] Silence PPC+ARM preprocessor warnings in atomicity.h

[Richard Earnshaw]

stewart@lab43.org said:
> On the subject of ARM and libstdc++, currently my native
> armv[3,4]l-linux builds hang during 'make check'.  In the end I've
> simply been killing off 'mkcheck', and allowing the builds to finish.
> I won't be able to get more details until today's build catches up in
> another few hours.  I would be willing to help track this down, I
> simply have no idea where to start looking. 

It's a call insn getting erroneously turned into a tailcall.  I'm testing 
a patch right now.

R.