More shader goodies & slight performance boost in CPU-bound games

Picking up from where we left before in the experimental build, shaders were being compiled async but we ran into a small, big issue. When you had accumulated a bunch of shaders - like maybe 1000+ - you'd run into a small issue: when you'd play the game again, you'd have to recompile all those 1000+ shaders at the start of the game, every single time. That was a horrible experience I'm sure and I don't think none of us finish games in one sitting. So, I asked AI to generate me a screen at the start and it did. Truly marvelous stuff, I tell you. Also, the cache isn't invalidated at the start anymore, as it shouldn't, so consequent shader compilations are considerably faster. From 4-5 minutes to 20-25 seconds.

Changes:

• Added a shader compilation screen at the start, before completely booting into the game.
• Pulled from azahar-emu#2318 - referenced by original Dekopon project. This gives a really nice 10-20% performance boost in CPU-bound games. It is a bit experimental but it works really well. Free performance boost, yay!
• Modified IO to be faster and more accurate. This was primarily meant to be aimed at Pokemon games, where jumping into battle caused the frames to drop to like 3-4 FPS for a second or two. The FPS still drops but they're less noticeable.

Read the older experimental changelog: #v1.0.0.3-rai for other changelog if you haven't updated.

Lemme know if any game crashes, since this is highly experimental and I probably don't know what I am doing.

PS. I am looking for someone to design a custom design for my fork pretty pls. Not paid since I don't expect to be paid for this either, its all for the community!