Code inlining, cleanup

[Archie-osu]

Just cleaned up the code a little, all original functionality should be intact - the CheckDecompiler.csx script yields the exact same values before / after the changes.

I don't know much C#, so code criticism is welcome, and I'll gladly update this PR.

[Miepee]

Is this going to be obsoleted by the new decompiler?

[colinator27]

This is pretty much fully obsolete now with the new decompiler, so I'll close this, at least for now.