Help test the Vulkan backend before the 1.5 release

[Henrik]

Hi all,

If you have a Vulkan-capable PC, phone or device, please get the latest build at https://buildbot.orphis.net/ppsspp/ , then post here and report if it works, especially if you have any major issues like crash during startup or similar. Note that Vulkan is currently only working on Windows and Android, Linux support will come later.

I'll start:

PC with nVidia Geforce 770GTX: Works fine, faster than OpenGL
nVidia Shield TV (Geforce): Works fine, faster than OpenGL
Nexus 5X (Adreno GPU): Works fine, much faster than OpenGL
Galaxy S8+ (International, Mali GPU): Works fine, much faster than OpenGL