cmd/8l/obj.c: NetBSD passes the test, Hnetbsd added.

myrtle$ go version
go version devel +d533352b414d Sat Mar 09 05:39:15 2013 +0100 netbsd/386
myrtle$ time go test -ldflags -hostobj ../misc/cgo/test
ok      _/var/project/GoLang/misc/cgo/test      10.962s
   68.63s real    49.60s user    19.06s system
myrtle$ uname -a
NetBSD myrtle.plan9.local 6.0_BETA2 NetBSD 6.0_BETA2 (GENERIC) i386

R=rsc
CC=golang-dev
https://codereview.appspot.com/7641047

Committer: Russ Cox <rsc@golang.org>