[krbdev.mit.edu #2551] Or use BYTE_ORDER :-)

[Tom Yu via RT]

src/lib/crypto/aes/aesopt.h already checks for BYTE_ORDER, and various
other header-defined or predefined macros determining byte order.  We
aren't even using the autoconf endianness tests in that directory.
src/util/db2/include/db-int.h is another matter, though.