BlockLSTMV2

for x1 in unpack(x):
   i1, cs1, f1, o1, ci1, co1, h1 = LSTMBlock(
     x1, cs_prev, h_prev, w, wci, wcf, wco, b)
   cs_prev = cs1
   h_prev = h1
   i.append(i1)
   cs.append(cs1)
   f.append(f1)
   o.append(o1)
   ci.append(ci1)
   co.append(co1)
   h.append(h1)
 return pack(i), pack(cs), pack(f), pack(o), pack(ci), pack(ch), pack(h)
 
 Note that unlike LSTMBlockCell (and BlockLSTM) which uses ICFO gate layout,
 this op uses IFCO. So in order for the following snippet to be equivalent
 all gate-related outputs should be reordered.