Make UntrustedNodeAddress a newtype.

This will allow us to make it Send after the Rust upgrade.

components/script_traits/lib.rs

@@ -39,7 +39,9 @@ use serialize::{Encodable, Encoder};
 
 /// The address of a node. Layout sends these back. They must be validated via
 /// `from_untrusted_node_address` before they can be used, because we do not trust layout.
-pub type UntrustedNodeAddress = *const c_void;
+#[allow(raw_pointer_deriving)]
+#[deriving(Copy, Clone)]
+pub struct UntrustedNodeAddress(pub *const c_void);
 
 pub struct NewLayoutInfo {
     pub old_pipeline_id: PipelineId,