LLVM Clang Lands Initial SPIR-V Toolchain Support

An exciting LLVM development has landed in time for Christmas! Complementary to the LLVM SPIR-V back-end work that could soon be mainlined, Clang has now merged the initial SPIR-V toolchain support. This allows going from Clang to the SPIR-V intermediate representation that is conformant to the OpenCL environment specification -- such as for compiling OpenCL kernels into SPIR-V...