Add more upstream 1.31 changes.

[vanfanel]

Add more upstream 1.31 changes: -Swap cart/debug. for cart/bootrom. and use CART_BOOTROM instead of CART_MDFN_DEBUG in ss.cpp -Add sha256 "sha256_hasher" class needed for bootrom.* to build. -Add MDFN_enlsb() to mednafen-endian needed by "sha256_hasher" class to build (This was done in C instead of using C++ like upstream does, in order to avoid the extra mile of switching to the new C++ endian code). -Add timestamp update in SoundCPU_BusIntAck() -Incorporate SOUND_ResetSCSP() to sound.cpp, only used by STV for now (STV emulation is not incorporated).

This commit was mostly "aesthetic", I guess, but maybe future updates will use this new stuff. STV support was not incorporated from upstream, too much hassle for games that are already supported on the Saturn console.

[riggles1]

Please reconsider, a lot of us have been wishing for STV support for a long time, the games aren't the same and many had cutbacks when ported back to Saturn. Missing animation for Golden Axe The Duel and Groove on Fight for example. While other games are locked to the Japanese language like Sando-R or have gameplay differences to the home version like with Steep Slope Sliders. Then across the board you have faster loading screens, proper arcade service menu's and coin/credit support for arcade setups.

There's a ton to dive into with the ST-V, one reason some of us can't do it in standalone mednafen is because of the lack of CRTSwitchres that RA has. But overall having it in RA benefits a lot of people running different hardware.

A lot of ST-V Games emulate fairly poorly in MAME (layer errors, random crashes).

[vanfanel]

@riggles1 Problem is time. I won't have much time until next year. I will try to incorporate STV gradually, but I am not sure I'm up to the task, I would need support from someone who knows details about Mednafen internals, but it's creator seems to be unreacheable.

So, for now, this is what I can do.

[riggles1]

Thanks for the reply! That makes sense, it was more a reply just so that others seeing this don't dismiss STV support thinking it's the same as the Saturn ports.

Really appreciate the changes and consideration too :)