Fix torch.diagonal for torch.onnx.export when dim1<0 or dim2<0 (#111130)
in many cases, torch.diagonal will pass (dim1=-2, dim2=-1), onnx export will always fail in these cases
this pr try to fix the bug
Pull Request resolved: https://github.com/pytorch/pytorch/pull/111130
Approved by: https://github.com/thiagocrepaldi
