Calling Super on a native superclass method fails at runtime

A class that inherits from a built-in class (such as MemoryBlock) and overrides one of its methods cannot delegate to the inherited built-in implementation with Super: the Super call fails with a runtime type error when its result is used, and silently leaves the wrong value behind for calls that return nothing. Expected behaviour: Super.SomeNativeMethod(...) runs the built-in superclass implementation and returns its result, like any other method call.