ref: b4252aeded2d15592fe940e20f533f113000c61d
dir: /lib/std/test/sjlj.myr/
use std
var st
const main = {
	var jb
	st = 1
	if std.setjmp(&jb)
		std.put("nonlocal return\n")
		std.exit(st)
	;;
	st = 0
	std.put("doing jmp\n")
	dolongjmp(&jb)
	std.fatal("unreachable\n")
}
const dolongjmp = {jb
	std.longjmp(jb)
}