Running `get_dynamic_class_hook()` after `get_class_decorator_hook_2()`

Feature

It would be useful to run get_dynamic_class_hook() from plugins after get_class_decorator_hook_2() to support dynamic classes that inspect existing dataclasses / attrs classes.

Pitch

We have an internal mypy plugin that makes "partial" classes, where all required attributes are optional. It does this by examining the __init__ of an attrs class and creating a new __init__ for the new class where all args are now optional. This works in mypy 0.942, occasionally crashes in 0.950, and doesn't work at all in 0.960 (128661ccbf4396ed1538421c481f1773c7490169) because the attrs __init__ is not present during get_dynamic_class_hook().

Is there some way to work around this?

Beginne damit, die Plugin-Einstiegspunkte get_dynamic_class_hook() und get_class_decorator_hook_2() nachzuverfolgen und zu untersuchen, wie die Reihenfolge der Hooks die von attrs erzeugten init-Methoden sichtbar macht. Die Änderung ist abgeschlossen, wenn dynamische Klassen-Hooks vorhandene dataclasses oder attrs-Klassen nach der Decorator-Verarbeitung untersuchen können, mit Regressionsabdeckung für das hier beschriebene partial-class-Plugin-Szenario.