[quant] Support quantization of embedding lookup operators (#44207)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/44207
Use existing embedding_bag operator but set offsets to [0, 1, .. len(indices)]
Test Plan:
python test/test_quantization.py TestEmbeddingOps.test_embedding_byte
Imported from OSS
Reviewed By: vkuzo
Differential Revision: D23547385
fbshipit-source-id: ccce348bc192c6a4a65a8eca4c8b90f99f40f1b1
