Trying to build a project with a script that uses ArrayList.BinarySearch or IndexOf fails when targeting WP8 or WP8.1

To reproduce:
1. Create a new project
2. Create a new script
3. Add these lines to start:
ArrayList traList = new ArrayList ();
traList.Add (transform);
traList.BinarySearch (null);
4. Build for WP8 or WP8.1 - exception is thrown in console:
Error building Player: Exception: Error: method `System.Int32 System.Collections.ArrayList::BinarySearch(System.Object)` doesn't exist in target framework. It is referenced from Assembly-CSharp.dll at System.Void NewBehaviourScript::Start().