Support Negative Axis in Size in ONNX (#26436)
Summary:
Currently, we export invalid ONNX models when size() is used with a negative dim.
This PR fixes the issue and allows exporting these models to ONNX (ex: input.size(-1)).
Pull Request resolved: https://github.com/pytorch/pytorch/pull/26436
Reviewed By: hl475
Differential Revision: D17565905
Pulled By: houseroad
fbshipit-source-id: 036bc384b25de77506ef9fbe24ceec0f7e3cff8b
