Missed in 0b349f6f that Bterm is not closing fd.

OpenBSD is using pthreads now, so no need for tas.

Also reduce duplication: makecontext is per-arch not per-os-arch. May fix #353.

It may be that pthreads on NetBSD is now good enough, but the build as written (introduced in 23a2368 at my suggestion) is certainly broken, since both NetBSD.c and pthread.c define the same functions. If NetBSD does support pthreads now, then a few things should happen together: - libthread/sysofiles.sh should drop its top NetBSD case entirely - libthread/NetBSD.c should be deleted - libthread/NetBSD-*-asm.s should be deleted - include/u.h's NetBSD case should define PLAN9PORT_USING_PTHREADS and #include <pthread.h> For now, restore to less clearly broken build.

Linux 2.4 is dead. (The libthread code hasn't worked for Linux 2.4 for a long time.)

Linux.c was for Linux 2.4 and is no longer used directly, only indirectly because NetBSD.c was a 1-line file #including Linux.c. So mv Linux.c NetBSD.c. Also rm Linux-*-asm.s which was for Linux 2.4 as well.

More dead code.

Darwin 11.0.0 was Mac OS X 10.7.0 aka Lion. The previous version was Snow Leopard, which has been unsupported by Apple since February 2014.

Pretty sure FreeBSD 4 is gone now. :-)

This should have been deleted in 20f5692b (2012-07-14), which removed the mkfile and sysofiles.sh references to it.

They were just a duplicate of my(get|set)mcontext from the other assembly file, and unused from threadimpl.h. Change-Id: Id8003e5177ed9d37a7f0210037acbe55bbf7f708

Fixes #195. Signed-off-by: Dan Cross <cross@gajendra.net>

Fixes #3.