Update native support.
pub use std::vec::Vec;
+pub use std::rc::Rc;
+pub use std::cell::RefCell;
+pub use std::boxed::Box;
+pub use std::mem::{size_of, transmute};
pub fn storage(_key: &[u8]) -> Vec<u8> { vec![] }
pub fn storage_into<T: Sized>(_key: &[u8]) -> Option<T> { None }
