Add unique_ptr<NamedTensorMeta> field to TensorImpl (#21341)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/21341
ghimport-source-id: 06021b06864746571a904a1cfc0aaea5f8a12325
Differential Revision: D15717907
Pulled By: zou3519
fbshipit-source-id: 48ee76cf2f11a8b092be75ecac8d5faee68ca0d9
