Release GIL in Tensor indexing functions (#71728)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/71728
Fixes gh-68739
For simple indexing this adds a `gil_scoped_release` before calling
`set_item`. For tuple indexing, the slicing operation is done with the
GIL because otherwise it would have to re-aquire the GIL for each
element in the tuple. However, the GIL is released for the final
`copy_to` operation which is where the actual kernels are called.
Test Plan: Imported from OSS
Reviewed By: anjali411
Differential Revision: D33770047
Pulled By: albanD
fbshipit-source-id: 67304a65e2cbf3b3ba9843687d9c63926d29298f
(cherry picked from commit d0a85046b7a497df8f377ff43f1667982ede7f2a)
