> Yes, I made the build on a PPC machine. 

Hmm. Ronald's instructions say that the build machine must be
x86 for the build to work. I don't know what other
consequences using PPC would have; I recommend that we follow
these instructions until we understand them enough to change
them.

> I'm no expert on this, but maybe
> we should just get rid of the configure check and use the
> __LITTLE_ENDIAN__ and __BIG_ENDIAN__ macros.

That won't work, as not all compilers define these macros.
The 2.5 approach works fine (use the macros on OSX, and
use the configure test elsewhere). Unfortunately, that
support got removed in r63955. The patch in issue4060 looks
fine; I'm unsure why it hasn't been applied yet.