Add net_pos Tiles added during in-batch broadcast (#40078)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/40078
att. It's good to have net_pos for all the ops so that we can distinguish each op in minimizer in net_runner.
Test Plan: unittest
Reviewed By: ipiszy, ChunliF
Differential Revision: D22062748
fbshipit-source-id: 5266abdb6dde63055fdffdba6e8d65bd0f221d7b
