Since beginning last year, our team at Igalia has been involved in enabling ARB_gpu_shader_fp64 extension to different Intel generations: first Broadwell and later, then Haswell, now IvyBridge (still under review); so working on supporting Vulkan’s Float64 capability into Mesa was natural.
Today we have pushed the needed changes to plug SPIR-V’s Float64 support into Mesa and enable it on ANV driver (for those who don’t know it, ANV driver is the Intel’s open-source driver that implements Vulkan API in Mesa). So you will have this support available in next Mesa release if your Linux distribution packages this open-source Vulkan driver :-)
I would like to thank Jason Ekstrand for his reviews; and also Juan who worked together with me to make this support happen.