[mlir][py] partially use mlir_type_subclass for IRTypes.cpp
Port the bindings for non-shaped builtin types in IRTypes.cpp to use the
`mlir_type_subclass` mechanism used by non-builtin types. This is part of a
longer-term cleanup to only support one subclassing mechanism. Eventually, the
`PyConcreteType` mechanism will be removed.
This required a surgery in the type casters and the `mlir_type_subclass` logic
to avoid circular imports of the `_mlir.ir` module that would otherwise when
using `mlir_type_subclass` to define classes in the `_mlir.ir` module.
Tests are updated to use the `.get_static_typeid()` function instead of the
`.static_typeid` property that was specific to builtin types due to the
`PyConcreteType` mechanism. The change should be NFC otherwise.
llvm-project
deac2645 - [mlir][py] partially use mlir_type_subclass for IRTypes.cpp
