Created by: 1024er

• fix error info for rnn related api

• passed local test, test=develop

• double check the code

• double check the code, test=develop

• update 'shape' check in RNNCell, test=develop

• add long dtype to RNNCell

• fix long type in python3

Co-authored-by: XingWu01 wuxing@iie.ac.cn