[mlir] Return vectorized values instead of replacing (#144158)

Updates the linalg::vectorize function to return a
`FailureOr<VectorizationResult>` containing the values to replace the
original operation, instead of directly replacing the original
operation. This aligns better with the style of transforms used with the
TilingInterface, and gives more control to users over the lowering,
since it allows for additional transformation of the IR before
replacement.

There was already a `VectorizationResult` defined, which was used for
the internal vectorize implementation using `CustomVectorizationHook`s,
so the old struct is renamed to `VectorizationHookResult`.

Note for integration: The replacement of the original operation is now
the responsibility of the caller, so wherever `linalg::vectorize` is
used, the caller must also do
`rewriter.replaceOp(vectorizeResults->replacements)`.

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Signed-off-by: Max Dawkins <max.dawkins@gmail.com>

0 files changed, 0 insertions, 0 deletions