other non-NetBSD platforms as well (though they may need ALL_TARGET
tweaking):
- apparently some versions of Linux/gcc combinations require
the header file errno.h included in each file in order for
it to link (otherwise, it will compile (!?) but bail out
when linking)
- set ALL_TARGET to LOWER_OPSYS
this works for netbsd and linux, and should work for the other bsds
at least.
- set ALL_TARGET differently for IRIX
- use CFLAGS instead of hard-coded ABI flags for IRIX 6
- some install-sh/install can not handle multiple files/directories at
once. Newer bootstrapped versions can, but for systems that still
have the older one we may as well split this for better compatibility.
