Add fbgemm_qlinear_dynamic op (#23104)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/23104
ghstack-source-id: 87247148
As suggested in https://github.com/pytorch/pytorch/pull/22891, we will add an overload for ```torch.fbgemm_linear_int8_weight``` (dynamic quantized version of linear function) that takes PackedLinearWeight as input and is pretty much the same in signature as regular aten::linear.
Differential Revision: D16381552
fbshipit-source-id: 1ccc4174fd02c546eee328940ac4b0da48fc85e8
