[mlir][TilingInterface] Avoid looking at operands for getting slices to continue tile + fuse. (#107882)

Current implementation of `scf::tileConsumerAndFuseProducerUsingSCF`
looks at operands of tiled/tiled+fused operations to see if they are
produced by `extract_slice` operations to populate the worklist used to
continue fusion. This implicit assumption does not always work. Instead
make the implementations of `getTiledImplementation` return the slices
to use to continue fusion.

This is a breaking change

- To continue to get the same behavior of
`scf::tileConsumerAndFuseProducerUsingSCF`, change all out-of-tree
implementation of `TilingInterface::getTiledImplementation` to return
the slices to continue fusion on. All in-tree implementations have been
adapted to this.
- This change touches parts that required a simplification to the
`ControlFn` in `scf::SCFTileAndFuseOptions`. It now returns a
`std::optional<scf::SCFTileAndFuseOptions::ControlFnResult>` object that
should be `std::nullopt` if fusion is not to be performed.

Signed-off-by: MaheshRavishankar <mahesh.revishankar@gmail.com>

0 files changed, 0 insertions, 0 deletions