[Mlir-commits] [mlir] [mlir][python] Fixup the constantTypes of pdl.TypesOp (PR #75812)

[Maksim Levental]

makslevental wrote:

> rather than %0 = types which may result in PDL interpreter failure.

Sorry I'm not a `pdl` expert - what's the error? 

Although I agree this could/should be just `None`, since `OptionalAttr` here

```
def PDL_TypesOp : PDL_Op<"types"> {
  ...
  let arguments = (ins OptionalAttr<TypeArrayAttr>:$constantTypes);
  ...
}
```

but it feels like this is a bug in how `pdl_interp.check_types` handles `[]`.

https://github.com/llvm/llvm-project/pull/75812