depends on D150839
This diff uses `MlirTypeID` to register `TypeCaster`s (i.e., `[](PyType pyType) -> DerivedTy { return pyType; }`) for all concrete types (i.e., `PyConcrete<...>`) that are then queried for (by `MlirTypeID`) and called in `struct type_caster<MlirType>::cast`. The result is that anywhere an `MlirType mlirType` is returned from a python binding, that `mlirType` is automatically cast to the correct concrete type. For example:
```
c0 = arith.ConstantOp(f32, 0.0)
# CHECK: F32Type(f32)
print(repr(c0.result.type))
unranked_tensor_type = UnrankedTensorType.get(f32)
unranked_tensor = tensor.FromElementsOp(unranked_tensor_type, [c0]).result
# CHECK: UnrankedTensorType
print(type(unranked_tensor.type).__name__)
# CHECK: UnrankedTensorType(tensor<*xf32>)
print(repr(unranked_tensor.type))
```
This functionality immediately extends to typed attributes (i.e., `attr.type`).
The diff also implements similar functionality for `mlir_type_subclass`es but in a slightly different way - for such types (which have no cpp corresponding `class` or `struct`) the user must provide a type caster in python (similar to how `AttrBuilder` works) or in cpp as a `py::cpp_function`.
Reviewed By: ftynse
Differential Revision: https://reviews.llvm.org/D150927
Add a new OperationType handle type to the Transform dialect. This
transform type is parameterized by the name of the payload operation it
can point to. It is intended as a constraint on transformations that are
only applicable to a specific kind of payload operations. If a
transformation is applicable to a small set of operation classes, it can
be wrapped into a transform op by using a disjunctive constraint, such
as `Type<Or<[Transform_ConcreteOperation<"foo">.predicate,
Transform_ConcreteOperation<"bar">.predicate]>>` for its operand without
modifying this type. Broader sets of accepted operations should be
modeled as specific types.
Reviewed By: nicolasvasilache
Differential Revision: https://reviews.llvm.org/D135586
