Log Message:
[libretro-]snes9x[-gtk]: update to 1.61

- Restructured tile.cpp tile renderer from heavy macros into C++
  templates, significantly lowering compile time. (yoffy)
- MichaelBuckley provided a brand new MacOS port that is completely
  rewritten based on newer, supported APIs.
- Fixed an out-of-bound memory access in sound DSP. (Sour, byuu)
- Revert default SFX2 clock speed increase.
- Added a render position hack. Fixes glitches in several games.
- Allow an SRAM mapping up to 128KB.

Gtk:
- Added an option to show time. (taimoorgit)
- Use a submodule for glslang, because it doesn't guarantee API stability.
- Switched to GTK's C++ interface, gtkmm3. This effectively drops
  GTK+ 2.0 support.
- Joysticks can now be hotplugged. (jraby)

Unix:
- Added audio output threading. (yoffy)
- Added screensaver prevention on joystick use. (greg-kennedy)
- Fix YUY2 conversion. (greg-kennedy)
- Add alsa output support. (cjacker)
- Add I420 conversion. (cjacker)