Add Quantized Backend (#18546)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/18546
We'll expose all combinations of various ways of quantization in the top level dispatch key, that is we have AffineCPUTensor, PerChannelAffineCUDATensor, etc.
QTensor method added:
- is_quantized()
- item()
Differential Revision: D14637671
fbshipit-source-id: 346bc6ef404a570f0efd34e8793056ad3c7855f5
