CPPWriter: Dynamically call only instance methods
CPPWriter: Dynamically call only instance methods

If all_methods_callable_dynamically, we used to try to generate
dynamic dispatch stuff even for global methods or methods of
primitives.  Since there's no THIS here, this isn't possible.
So now we're a little more careful.

Plasmaworks/Rogue,AbePralle/Rogue,Plasmaworks/Rogue,Plasmaworks/Rogue,Plasmaworks/Rogue,AbePralle/Rogue