ONNX export for index_select (#21866)
Summary:
ONNX export for index_select
Pull Request resolved: https://github.com/pytorch/pytorch/pull/21866
Reviewed By: zrphercule
Differential Revision: D16471345
Pulled By: houseroad
fbshipit-source-id: 745c23ba8a3223b5ec59b924df7358a36a92518c
