Intra-graph reordering pass on Inductor scheduler IR (based on #100762) (#108091)
This PR implements intra-graph communication reordering pass on Inductor scheduler IR, based on Horace's previous PR #100762.
Main algorithm:
1. Greedily moves waits as late as possible (i.e. until we reach a use)
2. Greedily moves comms as early as possible (i.e. until we reach an input)
3. Move computes following simple heuristics to improve overlap.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/108091
Approved by: https://github.com/Chillee, https://github.com/wanchaol
