Assist: Fail move if no moves have been found

Moves.json

@@ -655,7 +655,11 @@
         "protect",
         "reflectable",
         "mirror"
-      ]
+      ],
+      "effect": {
+        "name": "ChangeTargetAtt",
+        "parameters": [-1]
+      }
     },
     {
       "name": "baneful_bunker",

Scripts/Interfaces/MoveTurnChoice.astypedef

@@ -3,5 +3,7 @@ type MoveTurnChoice {
     Pokemon@ User { get const; };
     LearnedMove@ Move { get const; };
     int8 Priority { get const; };
+    bool HasFailed { get const; };
+    void Fail();
     BaseTurnChoice@ opImplCast();
 }

Scripts/Moves/Assist.as

@@ -20,7 +20,7 @@ namespace Gen7 {
                 }
             } 
             if (possibleMoves.length == 0){
-                // TODO: Log failure.
+                move.Fail();
                 return;
             }
             auto i = battle.Random.Get(possibleMoves.length);