Add Nintendo Switch support (libnx)

[blueberrymuffin3]

Initial work to get SAME_CDI running on the nintendo switch through libnx.

Closes #11

Working:

• BIOS
• ISO/CUE roms
• Gameplay, input, video, audio etc...
• Tested with "Link: The Faces of Evil" and "Hotel Mario"
• Running at full speed or near full speed

Not working

• CHD roms (decompression error)
• Audio is crackly sometimes
• JIT (x86 only) (not sure if needed performance-wise)

Notes

• Includes import change from Update osdlib.h #19
• Requires my RetroArch branch: blueberrymuffin3/RetroArch#same-cdi-switch (Plan to upstream once everything is working)

Building

1. Install dependencies (see LibRetro Wiki)
2. Build SAME_CDI: make -f Makefile.libretro platform=libnx -j4
3. Copy same_cdi/same_cdi_libretro.a to RetroArch/libretro_libnx.a
4. Build RetroArch: make -f Makefile.libnx -Bj10

Running

1. Install RetroArch
2. Build or use my binary: same_cdi_libretro_libnx.zip
3. Copy NRO to /retroarch/cores/same_cdi_libretro_libnx.nro on SD

Note: Can probably be tested in switch emulator, but I'm not sure

Screenshots/Videos

TODO

Still needed

• BuildBot integration
• Possibly avoid changes to vendored dependencies (Are the Lua/SQLite/linenoise libraries actually needed/used?)
• Use proper defines/build flags (probably __SWITCH__ or HAS_LIBNX instead of __DEVKITPRO__)

[blueberrymuffin3]

Let me know if there is any interest in getting this PR merged so I can put some work into finishing it up.

[ZeROOFALL]

I've added this core to my deployment of retroarch on my switch I'm but having trouble getting it to successfully launch a game. I first converted my CHD files into bin/cue but gave up and tried the ISO/cue versions but still end up getting a fatal error telling me required files are missing and the machine cannot run. All the required bios files are present in the correct place to be recognized under the core info tab and I also have copies inside the folder the iso and cue files are located in. What else am I missing?