function scheduler_queue(packet) {
  var t = this.blocks[packet.id];
  if (t == null) return t;
  this.queueCount++;
  packet.link = null;
  packet.id = this.currentId;
  return tcb_checkPriorityAdd.call(t, this.currentTcb, packet);
}
Add the specified packet to the end of the worklist used by the task
associated with the packet and make the task runnable if it is currently
suspended.
@param {Packet} packet the packet to add