Python/ceval.c and many other places rely on __ppc__ (and __ppc64__) 
symbol defined like below.

Unfortunately on my Linux ppc __ppc__ is never defined while 
__powerpc__ is. Build fortunately failed so the problem was noticed.

The fix is to check for __powerpc__ and __powerpc64__ as for example 
glibc does.



#if defined(__ppc__) /* <- Don't know if this is the correct symbol; 
this
                           section should work for GCC on any PowerPC
                           platform, irrespective of OS.
                           POWER?  Who knows :-) */

__ppc__ is defined on MacOS X, __powerpc__ on Linux.

Only place when need check for both is Python/ceval.c