Vec2i, IntRect: Add unequal operator

src/etc-internal.h

@@ -88,6 +88,11 @@ struct Vec2i
 		return x == other.x && y == other.y;
 	}
 
+	bool operator!=(const Vec2i &other) const
+	{
+		return !(*this == other);
+	}
+
 	Vec2i &operator+=(const Vec2i &value)
 	{
 		x += value.x;
@@ -176,6 +181,11 @@ struct IntRect : SDL_Rect
 		        w == other.w && h == other.h);
 	}
 
+	bool operator!=(const IntRect &other) const
+	{
+		return !(*this == other);
+	}
+
 	Vec2i pos() const
 	{
 		return Vec2i(x, y);