Won't build on Debian and derivates (Fix inside!!)

[vanfanel]

Hi there,

Some distros like Debian and it's derivatives don't link glslang against SPIRV-Tools, which causes dolphin_libretro linking to fail.

It was fixed a couple of days ago on upstream Dolphin:

dolphin-emu@37d6fe6

...so please merge that so we can easily build on most popular Linux distros :)

[cscd98]

Thanks i'll be sure to include it in the next PR

[cscd98]

Included in #366