[mlir][Vector] Make elementwise-on-broadcast sinking handle splat consts (#150867)

There is a pattern that rewrites
elementwise_op(broadcast(x1 : T to U), broadcast(x2 : T to U), ...) to
broadcast(elementwise_op(x1, x2, ...) : T to U).

This pattern did not, however, account for the case where a broadcast
constant is represented as a SplatElementsAttr, which can safely be
reshaped or scalarized but is not a `vector.broadcast` or `vector.splat`
operation.

This patch fixes this oversight, prenting premature broadcasting.

This did result in the need to update some linalg dialect tests, which
now feature a less-broadcast computation and/or more constant folding.

0 files changed, 0 insertions, 0 deletions