script: Inline some hot functions used in flow constructions.

9% improvement in style recalc on the rainbow page.

src/components/script/dom/bindings/utils.rs

@@ -621,6 +621,7 @@ pub struct Reflector {
 }
 
 impl Reflector {
+    #[inline]
     pub fn get_jsobject(&self) -> *JSObject {
         self.object
     }