Add support for Sega Mega-CD 32X / Sega CD 32X (6 titles)

So far, bizhawk emulate perfectly all of my retro games except a few rare Sega CD 32X games, it would be nice if the emulator can support them.

[Spikestuff]

MegaCD/SegaCD: #1406

As for 32X well that's already supported.
Just some games have issues: #927

Here's DOOM 32X working for example:

[Sappharad]

@Spikestuff I don't think you understand this user's request.

There are but six games that require BOTH the 32x and MegaCD at the same time. As far as I know, we can't do that right now because BizHawk uses different cores for 32x and MegaCD.

https://segaretro.org/Sega_Mega-CD_32X

edit: it's six --yoshi

[Spikestuff]

@Sappharad I wrote my comment that way due to how the title is written as "Sega CD/32X" instead of having of using a space like it does in the comments and the part of written the comments also off'd me.

@YoshiRulz Suggestion to attempt to make it work in the PicoDrive core instead of the Gens core as Pico already has the 32x support.

[YoshiRulz]

Not sure if adding this to PicoDrive is the right way to do it, but it'll probably be easier so relabeled.

So far, only Fusion is able to support the 6 CD 32X games (I have never personally tested Surgical Strike though) . If I remember, that emulator is closed source right?

Yeah, old and closed source.

[nattthebear]

@Glitcholog I believe you're correct, since I tried one of these games in our picodrive core once, which, despite having mega CD and 32X attachments, didn't work with both of them enabled at once. (#927 (comment)) But is that documented somewhere? Do we know what's going on that 32X and CD needs that 32X or CD emulators don't do?

could always ask steve snake.... he is active on twitter. just putting this out there.