Fallback to CPU concat op to handle TensorCPU inputs (#15263)
Summary:
Fallback to CPU concat op to handle TensorCPU inputs
Pull Request resolved: https://github.com/pytorch/pytorch/pull/15263
Differential Revision: D13587030
Pulled By: yinghai
fbshipit-source-id: 010a8579d61c3beb8556eb92493a552b2ab0030c
