Sprite cache: Allow caching only required subset of sprite zoom levels

Enable for blitters based on 32bpp_optimized or SSE

src/core/alloc_type.hpp

@@ -120,4 +120,9 @@ struct FreeDeleter
 	void operator()(const void* ptr) { free(ptr); }
 };
 
+struct NoOpDeleter
+{
+	void operator()(const void* ptr) {}
+};
+
 #endif /* ALLOC_TYPE_HPP */