CUDA implementation of fakequant (#20252)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/20252
Add CUDA implementation for fakequant op for quantization aware training.
Reviewed By: zafartahirov
Differential Revision: D15243386
fbshipit-source-id: 37610ab046786ffc69aaec5235e5df8304c353d6
