<sys/endian.h>. It is needed to cross-build sparc64 on
RELENG_4 and to build sparc64 on say 5.0-DP1 (on systems
without <sys/endian.h>). This will be revisited when we
create RELENG_5.
Spotted by: make universe
This is needed on sparc64 (and maybe all OpenFirmware based machines) as
most [all?] OpenBoot PROM's require either an a.out or FCode boot image.
Submitted by: jake