Adjust bound_shape_inferencer to take 4 inputs for FCs (#41934)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/41934
The model exported from online training workflow with int8 quantization contains FCs with 4 inputs. The extra input is the quant_param blob. This diff is to adjust the bound_shape_inferencer and int8 op schema to get shape info for the quant_param input.
Test Plan:
```
buck test caffe2/caffe2/opt:bound_shape_inference_test
```
Reviewed By: yinghai
Differential Revision: D22683554
fbshipit-source-id: 684d1433212a528120aba1c37d27e26b6a31b403
