graphics: Software rendering when necessary

[hajimehoshi]

• There are some GPUs that have issues:
  • https://source.chromium.org/chromium/chromium/src/+/master:gpu/config/software_rendering_list.json
  • https://source.chromium.org/chromium/chromium/src/+/master:gpu/config/gpu_driver_bug_list.json
• There are no graphics API in some environments (e.g., Plan 9)

[beoran]

Plan 9 has avery clever /dev/bitblt witch the window manager uses for possibly accelerated 2D graphics. No 3D or OpenGL, though.

https://www.unix.com/man-page/plan9/2/graphics/