nnc hackathon - use new APIs in tests (#55497)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/55497
Migrating some of the NNC API's used in testing, from this issue: https://github.com/pytorch/pytorch/issues/55203
I covered the second half of `test_loopnest.cpp`, and migrated (1) and (2) in the above issue: `LoopNest::getLoopStmtsFor`, `splitWithTail`, and `splitWithMask`
Test Plan: Imported from OSS
Reviewed By: navahgar
Differential Revision: D27628625
Pulled By: bdhirsh
fbshipit-source-id: ec15efba45fae0bbb442ac3577fb9ca2f8023c2d
