pytorch

c9cae144 - fix unflatten_dense_tensor when there is empty tensor inside (#50321)

fix unflatten_dense_tensor when there is empty tensor inside (#50321) Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/50321 Quantization team reported that when there are two empty tensors are replicated among ranks, the two empty tensors start to share storage after resizing. The root cause is unflatten_dense_tensor unflattened the empty tensor as view of flat tensor and thus share storage with other tensors. This PR is trying to avoid unflatten the empty tensor as view of flat tensor so that empty tensor will not share storage with other tensors. Test Plan: unit test Reviewed By: pritamdamania87 Differential Revision: D25859503 fbshipit-source-id: 5b760b31af6ed2b66bb22954cba8d1514f389cca