PowerPC architecture specific stuff:

On OS X, the configure script tries to use gcc's -mdynamic-no-pic
option:

`-mdynamic-no-pic'
     On Darwin and Mac OS X systems, compile code so that it is not
     relocatable, but that its external references are relocatable.
     The resulting code is suitable for applications, but not shared
     libraries.


If you're using a G4 or G4, add --enable-altivec to your configure
options to get a vectorized version of the pseudo random number
generator.
