message: Add `static_state_saving_rnn` back to the `nn` module.
diff: @@ -160,6 +160,7 @@ nn.dynamic_rnn = rnn.dynamic_rnn
  nn.static_rnn = rnn.static_rnn
  nn.raw_rnn = rnn.raw_rnn
  nn.bidirectional_dynamic_rnn = rnn.bidirectional_dynamic_rnn
  +nn.static_state_saving_rnn = rnn.static_state_saving_rnn
  nn.rnn_cell = rnn_cell
  # Symbols whitelisted for export without documentation.
  