Rogue Squadron II Poor Performance

[Craftyawesome]

I do know of a couple things that are slower. 5.0-540 slowed down MMU games a bit https://dolphin-emu.org/blog/2016/09/06/booting-the-final-gc-game/#flipping-the-page-table. Defer EFB copies was also disabled a year ago https://github.com/dolphin-emu/dolphin/commit/9f5227d123ebfb505e4a94f86136d9c74ebfb52e#diff-f1b1706112583909a6fcc4265c87e4fd9d1ca083a06c3cb737d46a374ab41f7b