[RFC] TensorIR: A schedulable IR for TVM

@xqdan In Ansor, Fusion analysis is handled in TE with some straightforward heuristics, which I believe have covered our usecases. CC: @merrymercy @jcf94

Agree that ISL provides effective information about vectorization, and I believe there might be other competitive heuristics too. Tensorization is a more general topic that would be super interesting to explore :slight_smile: