Fix GH-9698: stream_wrapper_register crashes with FFI\CData

[bukka]

The context is provided before constructor is called so there needs to be a bit more checking in FFI and stream user wrapper.

[dstogov]

The fix is right, but FFI\CData is not an unique class that disables instantiation through a fake constructor. It seems like all of them may be used in unexpected ways. (e.g. you fix only property update, but some code may try to read property first).

It would be great to find a common solution to disable instantiation of some classes (this is probably for master branch only).

[bukka]

So stream wrapper actually calls constructor but after adding the context property so we would probably need some sort of checks in functions that call write_property (add_property_zval_ex), read_property and so on. It would probably help but extension could still call the handler directly so the question is whether it is not better to be addressed in each class - it means in this case FFI\CData should always check if it is initialized when writing, reading or unsetting props.

[bukka]

Anyway I will merge this as it fixes the actual problem and it is applicable as a bug fix.