Port emerald water functions into firered

src/ground.c

@@ -538,7 +538,7 @@ static void AnimDigDirtMound(struct Sprite *sprite)
     sprite->callback = WaitAnimForDuration;
 }
 
-void sub_80B94B4(u8 taskId)
+void AnimTask_HorizontalShake(u8 taskId)
 {
     u16 i;
     struct Task *task = &gTasks[taskId];