[NNC] Simplify and fix some bugs in Bounds Inference (#47450)
Summary:
Refactors NNC bounds inference to use the dependency analysis added in https://github.com/pytorch/pytorch/issues/46952. This ends up being a pretty good simplification because we no longer need the complicated bound merging code that we used to determine contiguous ranges. There were no usages of that code and the memory dependency analyzer is closer to what we want for those use cases anyway.
Added tests for a few cases uncovered by the existing bounds inference test - much of the coverage for this feature is in tests of it's uses: rfactor, computeAt and cacheAccesses.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/47450
Reviewed By: heitorschueroff
Differential Revision: D24834458
Pulled By: nickgg
fbshipit-source-id: f93e40b09c0745dcc46c7e34359db594436d04f0
