GitLab

For Linux, this requires additional #defines, see
https://gist.github.com/panzi/6856583#gistcomment-1656524



Placing those #defines into portable_endian.h would mean we
depend on the specific order of #includes (whatever pulls
in endian.h first, including other system includes). Avoid
this by using symbols provided "globally" via the Makefile.

Also nuke the _NETBSD_SOURCE definition in fel.c
Signed-off-by: Bernhard Nortmann <bernhard.nortmann@web.de>