Accept input tensor with 0-dim batch size for MultiLabelMarginLoss (#46975)
Summary:
Fix for one of the layers listed in https://github.com/pytorch/pytorch/issues/12013 or https://github.com/pytorch/pytorch/issues/38115
Pull Request resolved: https://github.com/pytorch/pytorch/pull/46975
Reviewed By: mruberry
Differential Revision: D25719980
Pulled By: ngimel
fbshipit-source-id: 83414bad37c0b004bc7cced04df8b9c89bdba3e6
