[ONNX] Update slice symbolic function (#42935)
Summary:
During scripting, combination of shape (or size()) and slice (e.g x.shape[2:]) produces following error:
slice() missing 1 required positional argument: 'step'
This happens because aten::slice has 2 signatures:
- aten::slice(Tensor self, int dim, int start, int end, int step) -> Tensor
- aten::slice(t[] l, int start, int end, int step) -> t[]
and when a list is passed instead of tensor the 2nd of the two slice signatures is called, and since it has 4 instead of 5 arguments it produces the above exception.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/42935
Reviewed By: houseroad
Differential Revision: D23398435
Pulled By: bzinodev
fbshipit-source-id: 4151a8f878c520cea199b265973fb476b17801fe
