Remove usage of unstable feature "raw"

components/layout/lib.rs

@@ -4,7 +4,6 @@
 
 #![deny(unsafe_code)]
 #![feature(box_patterns)]
-#![feature(raw)]
 
 extern crate app_units;
 extern crate atomic_refcell;
@@ -92,3 +91,12 @@ pub use self::data::LayoutData;
 // We can't use servo_arc for everything in layout, because the Flow stuff uses
 // weak references.
 use servo_arc::Arc as ServoArc;
+
+/// Stable copy of std::raw::TraitObject
+/// test/unit/layout/lib.rs asserts that the memory layout matches.
+#[repr(C)]
+#[derive(Clone, Copy)]
+pub struct TraitObject {
+    pub data: *mut (),
+    pub vtable: *mut (),
+}