That thread is talking about SPIR (the OpenCL binary shader format) in the OpenCL implementation, not SPIR-V (the Vulkan binary shader format, which has also been adopted by other APIs) in the Vulkan implementation.
That thread is talking about SPIR (the OpenCL binary shader format) in the OpenCL implementation, not SPIR-V (the Vulkan binary shader format, which has also been adopted by other APIs) in the Vulkan implementation.