EmbeddingBag w/ differentiable per_sample_weights (#18957)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/18957
ghimport-source-id: 7396ca08b137ea40f04285764a9d9a6d4f19227e
Reviewed By: cpuhrsch
Differential Revision: D14856526
Pulled By: zou3519
fbshipit-source-id: 949faea219c7c02ad981b1db610a477194d3f5c9
