avm2: Remove dead init_display_object fn

core/src/avm2/object.rs

@@ -1236,13 +1236,6 @@ pub trait TObject<'gc>: 'gc + Collect + Debug + Into<Object<'gc>> + Clone + Copy
         None
     }
 
-    /// Associate this object with a display object, if it can support such an
-    /// association.
-    ///
-    /// If not, then this function does nothing.
-    fn init_display_object(&self, _context: &mut UpdateContext<'_, 'gc>, _obj: DisplayObject<'gc>) {
-    }
-
     fn init_application_domain(&self, _mc: &Mutation<'gc>, _domain: Domain<'gc>) {
         panic!("Tried to init an application domain on a non-ApplicationDomain object!")
     }

core/src/avm2/object/stage_object.rs

@@ -5,9 +5,7 @@ use crate::avm2::object::script_object::ScriptObjectData;
 use crate::avm2::object::{ClassObject, Object, ObjectPtr, TObject};
 use crate::avm2::value::Value;
 use crate::avm2::Error;
-use crate::context::UpdateContext;
 use crate::display_object::DisplayObject;
-use crate::display_object::TDisplayObject;
 use gc_arena::{Collect, GcCell, GcWeakCell, Mutation};
 use std::cell::{Ref, RefMut};
 use std::fmt::Debug;
@@ -128,11 +126,6 @@ impl<'gc> TObject<'gc> for StageObject<'gc> {
         self.0.read().display_object
     }
 
-    fn init_display_object(&self, context: &mut UpdateContext<'_, 'gc>, obj: DisplayObject<'gc>) {
-        self.0.write(context.gc_context).display_object = Some(obj);
-        obj.set_object2(context, (*self).into());
-    }
-
     fn value_of(&self, _mc: &Mutation<'gc>) -> Result<Value<'gc>, Error<'gc>> {
         Ok(Value::Object(Object::from(*self)))
     }