byuu says:

This WIP fixes all the critical pending issues I had open. I'm sure
there's many more that simply didn't make their way into said list. So
by all means, please report important issues you're aware of so they can
get fixed.

Changelog:

  - ruby: add variable texture support to GDI video driver [bug
    reported by Cydrak]
  - ruby: minor cleanups to XShm video driver
  - ruby: fix handling of up+down, left+right hat cases for XInput
    driver [bug reported by Cydrak]
  - nall: fixed vector class so that compilation with GCC 7.1 should
    succeed [SuperMikeMan]
  - sfc: initialize most DSP registers to random values to fix Magical
    Drop [Jonas Quinn]
  - sfc: lower PPU brightness when luma=0 from 50% scale to 25% scale;
    helps scenes like Final Fantasy III's intro