[quant] Add support for multiple inputs in fusion pattern (#73572)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/73572
Previously we can't specify how to get extra inputs for fused ops in backend_config_dict,
for example, for patterns like:
(torch.add, (nn.BatchNorm2d, nn.Conv2d), MatchAllNode)
where nn.Conv2d is the root node, the extra MatchAllNode (the input for original torch.add) would be lost
This PR added a "extra_inputs_getter" key in the backend_config_dict, which allows user to provide a function,
that can return a list of extra input node for the fused op given the matched node pattern. In this case,
we need a function that returns the node that matches with `MatchAllNode`, it would be something like the following:
```
def extra_inputs_getter(pattern):
add, conv_bn, extra_input = pattern
return [extra_input]
```
Test Plan:
python test/test_quantization.py TestFuseFx.test_fusion_pattern_with_multiple_inputs
Imported from OSS
Reviewed By: vkuzo
Differential Revision: D34553210
fbshipit-source-id: 748f8ce20974438458a39dbe9eae75281156c227
(cherry picked from commit be748526480e811874dbca64b1cf3bf4950f0393)
