Replay recording / playback

This may require some thought, but having buttons that can trigger the replay functionality added in hrydgard/ppsspp#10888 would be useful.

The goal would be a way to quickly debug issues that occur from a save state or from startup with a sequence of commands.  Ideally it'd always be unthrottled for this usecase, as long as frameskip unthrottle is disabled.

-[Unknown]