[Core/SCD] improved savestate
[Core/SCD] improved savestate

Oggom/Genesis-Plus-GX,frangarcj/Genesis-Plus-GX,DavidKnight247/Genesis-Plus-GX,Oggom/Genesis-Plus-GX,frangarcj/Genesis-Plus-GX,DavidKnight247/Genesis-Plus-GX,DavidKnight247/Genesis-Plus-GX,frangarcj/Genesis-Plus-GX,DavidKnight247/Genesis-Plus-GX,Oggom/Genesis-Plus-GX,frangarcj/Genesis-Plus-GX,Oggom/Genesis-Plus-GX