Created by: tonyyang-svail

The unit tests of batch_norm and layer_norm depend on deprecated backward C++ implementation.

https://github.com/PaddlePaddle/Paddle/blob/b2a1c9e8b7f0fab5f81282783acadc2d35f3e207/python/paddle/fluid/tests/unittests/test_batch_norm_op.py#L23-L31

https://github.com/PaddlePaddle/Paddle/blob/b2a1c9e8b7f0fab5f81282783acadc2d35f3e207/python/paddle/fluid/tests/unittests/test_layer_norm_op.py#L73-L81