The `__eq__` method from our base class was not getting called, because we defined `tp_hash` as `NotImplemented`. Per [the docs on `tp_hash`](https://docs.python.org/3/c-api/typeobj.html#c.PyTypeObject.tp_hash), `tp_hash` and `tp_richcompare` are inherited together, so defining `tp_hash` was inhibiting the inheritance of `tp_richcompare`.
PiperOrigin-RevId: 465184018
Lots of changes but it's all just moving things around.
Backward-compatible stub #include's have been provided for now.
upb_Arena/upb_Status have been split out from upb/upb.?
upb_Array/upb_Map/upb_MessageValue have been split out from upb/collections.?
upb_ExtensionRegistry has been split out from upb/msg.?
upb/decode_internal.h is now upb/internal/decode.h
upb/mini_table_accessors_internal.h is now upb/internal/mini_table_accessors.h
upb/table_internal.h is now upb/internal/table.h
upb/upb_internal.h is now upb/internal/upb.h
PiperOrigin-RevId: 456297617
The previous change did not have the desired effect, because the generated code uses the class named "Message" instead of "CMessage."
There was no real need to use the class "CMessage" instead of "Message." The new name is simpler and will make the previous change work.
PiperOrigin-RevId: 449309343