Summary:
This diff is part of a bigger effort to remove the RTTI flags.
To do so we need to remove occurrences of `dynamic_cast` and other functions that rely on runtime
type informations.
Changelog:
[Internal][Changed] - Removed extra asserts relying on dynamic_cast
Reviewed By: JoshuaGross
Differential Revision: D30483554
fbshipit-source-id: 92b31281841a92c7b43e918938248431265dd654