[mlir][vector] Add lower-vector-multi-reduction pass (#87333)

This MR adds the `lower-vector-multi-reduction` pass to lower the
vector.multi_reduction operation.

While the Transform Dialect includes an operation,
`transform.apply_patterns.vector.lower_multi_reduction`, intended for a
similar purpose, its utility is limited to projects that have adopted
the Transform Dialect. Recognizing that not all projects are equipped to
integrate this dialect, the proposed pass serves as a vital standalone
alternative. It ensures that projects solely dependent on the
traditional pass infrastructure can also benefit from the optimized
lowering of `multi_reduction` operation.

---------

Co-authored-by: Xiaolei Shi <xiaoleis@nvidia.com>

0 files changed, 0 insertions, 0 deletions