bind_func optimization

Binding class functions to call always involves a malloc/free combination at the moment. It sets up the most generic scenario where the function will be passed around as a shared function.

Once the first optimization setup is done, this is a strong candidate for fixing. Most class calls do not require this setup.

It's also questionable whether a shared pointer makes sense here. If the source is shared it can be helpful, but if the source isn't shared it seems wrong.