Fixed RNNImplBase reset and flat_weights methods to handle bidirectional flag correctly (#22493)
Summary:
Fixing https://github.com/pytorch/pytorch/issues/19545:
Changed torch/csrc/api/src/nn/modules/rnn.cpp to be consistent with torch/nn/modules/rnn.py
Pull Request resolved: https://github.com/pytorch/pytorch/pull/22493
Differential Revision: D16111433
Pulled By: pbelevich
fbshipit-source-id: edfa41e8a9889d64918998dc7c46b8763fdf5765
