llvm-project

21edad7d - [mlir][sparse] set up the skeleton for SparseTensorLevel abstraction. (#75645)

[mlir][sparse] set up the skeleton for SparseTensorLevel abstraction. (#75645) Note that at the current moment, the newly-introduced `SparseTensorLevel` classes are far from complete, we plan to migrate code generation related to accessing sparse tensor levels to these classes in the near future to simplify `LoopEmitter`.