Preserve memory format for torch.cat on CUDA (#34526)
Summary:
fix https://github.com/pytorch/pytorch/issues/34084
cc: ptrblck VitalyFedyunin
Pull Request resolved: https://github.com/pytorch/pytorch/pull/34526
Differential Revision: D20371847
Pulled By: ngimel
fbshipit-source-id: e3b1a34caff2db8099ad9afe91bf9b473d5da6e8
