add SAFE_DIV macro and usages

src/field_effect.c

@@ -3668,14 +3668,8 @@ static void Task_MoveDeoxysRock_Step(u8 taskId)
         data[5] = sprite->pos1.y << 4;
 
         // UB: Possible divide by zero
-        #ifdef UBFIX
-        #define DIVISOR (data[8] ? data[8] : 1);
-        #else
-        #define DIVISOR (data[8])
-        #endif
-
-        data[6] = ((data[2] << 4) - data[4]) / DIVISOR;
-        data[7] = ((data[3] << 4) - data[5]) / DIVISOR;
+        data[6] = SAFE_DIV(((data[2] << 4) - data[4]), data[8]);
+        data[7] = SAFE_DIV(((data[3] << 4) - data[5]), data[8]);
         data[0]++;
         // fallthrough
     case 1: