Currently produces.

```
TEST: tile_once
None
error: 'transform.with_pdl_patterns' op expects only pattern and top-level transform ops in its body
// Verification failed, printing generic form
"builtin.module"() ({
  "transform.with_pdl_patterns"() ({
  ^bb0(%arg0: !pdl.operation):
    "transform.structured.canonicalized_sequence"(%arg0) ({
    ^bb0(%arg1: !pdl.operation):
      %0 = "transform.pdl_match"(%arg1) {pattern_name = @foo} : (!pdl.operation) -> !pdl.operation
      %1:3 = "transform.structured.tile"(%0) {interchange = [], sizes = [32, 16]} : (!pdl.operation) -> (!pdl.operation, !pdl.operation, !pdl.operation)
      %2 = "transform.structured.pad"(%1#0) {hoist_paddings = [], pack_paddings = [], padding_dimensions = [], padding_values = [], transpose_paddings = []} : (!pdl.operation) -> !pdl.operation
      %3 = "transform.structured.vectorize"(%2) {vectorize_padding = true} : (!pdl.operation) -> !pdl.operation
      "transform.bufferize"() : () -> ()
      "transform.lower_vectors"() {contraction_lowering = "outerproduct", multireduction_lowering = "innerreduce", split_transfers = "linalg-copy", stages = [0, 1, 2, 3, 4, 5, 6], transpose_avx2_lowering = false, transpose_lowering = "eltwise", unroll_vector_transfers = true} : () -> ()
      "transform.lower_to_llvm"() {enable_amx = false, enable_arm_neon = false, enable_arm_sve = false, enable_async = false, enable_index_optimizations = false, enable_x86vector = false, reassociate_fp_reductions = false} : () -> ()
    }) : (!pdl.operation) -> ()
  }) : () -> ()
}) : () -> ()

error: unregistered operation 'transform.structured.pad' found in dialect ('transform') that does not allow unknown operations
```