avm2: Don't use a `Class`'s first `ClassObject` for its VTable if more than one `ClassObject` had been constructed for the class

core/src/avm2/class.rs

@@ -295,6 +295,14 @@ impl<'gc> Class<'gc> {
         &self.class_objects
     }
 
+    pub fn class_object(&self) -> Option<ClassObject<'gc>> {
+        if self.class_objects.len() == 1 {
+            Some(self.class_objects[0])
+        } else {
+            None
+        }
+    }
+
     /// Construct a class from a `TranslationUnit` and its class index.
     ///
     /// The returned class will be allocated, but no traits will be loaded. The

core/src/avm2/optimize.rs

@@ -38,9 +38,8 @@ impl<'gc> Locals<'gc> {
         // after the ClassObject refactor
         self.0[index] = class
             .read()
-            .class_objects()
-            .get(0)
-            .map(|c| ValueType::Class(*c))
+            .class_object()
+            .map(ValueType::Class)
             .unwrap_or(ValueType::Any);
     }
 
@@ -79,9 +78,8 @@ impl<'gc> Stack<'gc> {
         self.0.push(
             class
                 .read()
-                .class_objects()
-                .get(0)
-                .map(|c| ValueType::Class(*c))
+                .class_object()
+                .map(ValueType::Class)
                 .unwrap_or(ValueType::Any),
         );
     }