Migrate binary_cross_entropy_backward from CUDA_tensor_apply4 to (#33995)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/33995
TensorIterator
Test Plan: Imported from OSS
Differential Revision: D20196790
Pulled By: VitalyFedyunin
fbshipit-source-id: c0c231a20e6e69fc3c68c3ac5082b20f2feb6158
