pytorch->onnx->ncnn flatten(squueze) problem

[ForestWang]

Dear Sir:

1. I trained the model with pytorch, the forward has below operations:
   x = self.avgpool(x)#x=[1,1024,1,1]
   x = x.view(x.size(0), -1)
   x = self.fc(x)

I can convert the pytorch model to onnx successfully, but when convert onnx model to ncnn, got "flatten not supported yet" problem.

2. then i change the forward code to:
   x = self.avgpool(x)#x=[1,1024,1,1]
   x = torch.squeeze(x,2)
   x = torch.squeeze(x,2)
   x = self.fc(x)
   I can convert the pytorch model to onnx successfully too, but when convert onnx model to ncnn, got "squeeze not supported yet" problem.

i have no idea on how to resolve this problem.
could you help @nihui ?
thank you very much!

[nihui]

flatten support added bbe044f