Reconsider TensorDomain::setLoopDomain, TensorDomain::broadcast, TendorDomain::additional_ids_

[naoyam]

TensorDomain::setLoopDomain allows for a new loop domain to have extra IDs. This is meant to introduce a broadcast ID.

TensorDomain::broadcast can also be used to introduce a new broadcast ID. The added broadcast ID is kept in TensorDomain::additional_ids_.

These two interfaces have some overlap. We should consider cleaning them up and possibly merging them to a single interface.

One concern with just using setLoopDomain is that any transformation history of extra IDs in the new loop domain would not be captured in TensorDomain::allIDs unless it's part of the BFS traversal between the logical and the new loop domains.

Related: https://github.com/NVIDIA/Fuser/pull/2987/files#r1771874761

Tagging @naoyam and @zasdfgbnm

[kevinstephano]

Is this done?

[naoyam]

Not yet. These are new interfaces and I think we are still learning what they should look like.