Cache IOrderValidator traits on World

OpenRA.Game/World.cs

@@ -142,6 +142,8 @@ namespace OpenRA
 		public readonly ScreenMap ScreenMap;
 		public readonly WorldType Type;
 
+		public readonly IValidateOrder[] OrderValidators;
+
 		readonly GameInformation gameInfo;
 
 		// Hide the OrderManager from mod code
@@ -203,6 +205,7 @@ namespace OpenRA
 			ActorMap = WorldActor.Trait<IActorMap>();
 			ScreenMap = WorldActor.Trait<ScreenMap>();
 			Selection = WorldActor.Trait<ISelection>();
+			OrderValidators = WorldActor.TraitsImplementing<IValidateOrder>().ToArray();
 
 			// Reset mask
 			LongBitSet<PlayerBitMask>.Reset();