Log Message:
Fix, hopefully, broken build on NetBSD 4.x, based on observations by
Robert Elz in PR 42083.

bsd.own.mk tags "all" with .NOTMAIN, so including bsd.own.mk before
defining "all" causes it to be skipped in favor of whatever comes next
in the makefile. Hack around this by putting "all:;" at the top.

I can't *really* test it because the syscalls script blows its mind if
given a NetBSD 5.x syscalls.master file.