examples: fix compilation with -prod

examples/2048/2048.v

@@ -455,7 +455,6 @@ fn (mut app App) ai_move() {
 		move_idx := int(move)
 		predictions[move_idx].move = move
 		mut mpoints := 0
-		mut mshifts := 0
 		mut mcmoves := 0
 		for _ in 0 .. predictions_per_move {
 			mut cboard := app.board
@@ -479,7 +478,6 @@ fn (mut app App) ai_move() {
 				}
 			}
 			mpoints += cboard.points
-			mshifts += cboard.shifts
 			mcmoves += cmoves
 		}
 		predictions[move_idx].mpoints = f64(mpoints) / predictions_per_move

examples/game_of_life/modules/automaton/automaton.v

@@ -23,6 +23,7 @@ pub fn (a &A2D) set(x int, y int, newval int) {
 		mut e := &int(0)
 		e = a.data + y * a.maxx + x
 		*e = newval
+		_ = e // TODO compiler bug, this is not necessary
 	}
 }
 
@@ -31,6 +32,7 @@ pub fn (a &A2D) get(x int, y int) int {
 	unsafe {
 		mut e := &int(0)
 		e = a.data + y * a.maxx + x
+		_ = e
 		return *e
 	}
 }