depend on namespace pollution and as such become more portable. This
means including headers like <sys/types.h> or <stdlib.h>, but also
making sure we include system/host headers before local headers.
While here: define ENOATTR as ENOMSG in mtree.c. There is no ENOATTR
on Linux.
With this, makefs is ready for compilation on macOS and Linux.
This is taken from the NetBSD versions listed below and adapted to the
makefs version in FreeBSD, along with a bug fix from cem@ that will be
sent to NetBSD.
Reviewed by: pfg
Approved by: re (gjb)
Obtained from: NetBSD
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D6835