Just one attribute allow you to make reorderable list from any serializable list or array.

Usage:
Add ReorderableAttribute to any serializable array or list. That's it. Now you can use all advantages of reorderable editor list.

Example:
[Reorderable] public int[] array;

Unfortunately existing Unity versions has some architectural limitations wich does not allow to use UnityEngine.Object with reorderable list directly. But you can use wrapper:
[System.Serializable]
public class Wrapper {
        public GameObject objectValue;
}
[Reorderable] public Wrapper[] wrappersArray;