Adjust bound_shape_inferencer to take 4 inputs for FCs (#41452)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/41452
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 to get shape info for the quant_param input.
Test Plan:
```
buck test caffe2/caffe2/opt:bound_shape_inference_test
```
Reviewed By: anurag16
Differential Revision: D22543215
fbshipit-source-id: 0977fca06630e279d47292e6b44f3d8180a767a5
