func (l *gList) pop() *g {
	gp := l.head.ptr()
	if gp != nil {
		l.head = gp.schedlink
	}
	return gp
}

//go:linkname setMaxThreads runtime/debug.setMaxThreads
func setMaxThreads(in int) (out int) {
	lock(&sched.lock)
	out = int(sched.maxmcount)
	if in > 0x7fffffff { // MaxInt32
		sched.maxmcount = 0x7fffffff
	} else {
		sched.maxmcount = int32(in)