e1c5cbc09c
This allows much better verification messages in consuming ops that properly declare
`TransformHandleTypeInterface` on their operands.
Downstream tests can be updated with a command resembling:
```
git grep -l "structured\.match" mlir/test | xargs -i sed -i {} -e "s/\(structured.match.*\)/\1 : (\!pdl.operation) -> \!pdl.operation/g"
```
Differential Revision: https://reviews.llvm.org/D142643