#79 Fix endianness detection on 64-bit PowerPC

[Sébastien Villemot]

ATLAS incorrectly detects big-endian 64-bit PowerPC platforms as being little endian.

The reason is that it tests whether the macro ORDER_LITTLE_ENDIAN is defined in CONFIG/src/SpewMakeInc.c. But this macro is defined even on big-endian systems. The right tests is to check whether BYTE_ORDER == ORDER_LITTLE_ENDIAN (at least with GCC).

I attach a patch for ATLAS 3.10.3 that is applied to the Debian package. It is straightforward to adapt it for ATLAS 3.11 branch, where two instances of the same test need to be fixed.

[R. Clint Whaley]

Applied in basefiles, should be fixed for 3.10.4.