* Invoke both legacy and UNSAFE_ lifecycles when both are present
This is to support edge cases with eg create-react-class where a mixin defines a legacy lifecycle but the component being created defines an UNSAFE one (or vice versa).
I did not warn about this case because the warning would be a bit redundant with the deprecation warning which we will soon be enabling. I could be convinced to change my stance here though.
* Added explicit function-type check to SS ReactPartialRenderer