There is no /usr/include/endian.h equivalent on z/OS, but the
compiler will define macros to indicate endianness on host and
target hardware. This adds a test for these macros as a last
resort for determining byte order.
Signed-off-by: David Michael <fedora.dm0@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>