Parts of syscall wrapper for FreeBSD
Merge branch 'master' of https://github.com/oridb/mc
Add initial cut for freebsd start code.

	Mostly, we use %rdi instead of %rsp for the args.
Merge branch 'master' of https://github.com/oridb/mc
Merge branch 'master' of https://github.com/akoshibe/mc
Merge remote-tracking branch 'origin/freebsd-port'
more modifications for FreeBSD port
Spit out the runtime from libstd.

	This will allow linking code without libstd, as well
	as fixing link order on freebsd.

	Freebsd seems to be picky aobut where '_start' is
	searched from.
Simplify runtime overrride scheme.

	Just provide a '-r' option that lets you point to any
	runtime that you want.