unbounded-spsc: Sender::send pointer-as-value transmute causes OOB read and fake-Arc drop under TX/RX race

unbounded_spsc is an "unbounded" extension of bounded_spsc_queue. In versions 0.2.0 and prior, sender::send pointer-as-value transmute causes OOB read and fake-Arc drop under TX/RX race. At time of publication, there are no publicly available patches.