Allow structseq to be input of operators where tuple is expected (#17208)
Summary:
Currently the following code gives an error on python 2 because `ret` is a structseq which is not a tuple
```python
ret = a.max(dim=0)
ret1 = torch.max(a, dim=0, out=ret)
```
This PR modify tuple check in python arg parser to allow structseq to be input of operators where tuple is expected, which would make the above code work.
Depend on: https://github.com/pytorch/pytorch/pull/17136
Partially fixes: https://github.com/pytorch/pytorch/issues/16813
Pull Request resolved: https://github.com/pytorch/pytorch/pull/17208
Differential Revision: D14280198
Pulled By: VitalyFedyunin
fbshipit-source-id: beffebfd3951c4f5c7c8fe99a5847616a89491f3
