LLVM 3.4 SPIR module?

The spir-encoders within the SPIR-Tools repository are used to convert LLVM 3.4 or LLVM 3.5 SPIR modules into LLVM 3.2 encoding, according to the readme files. How can LLVM 3.4 or LLVM 3.5 SPIR modules be generated?

The libclc headers do not seem to support SPIR, and of course the Khronos-patched Clang generates LLVM 3.2 SPIR.

Thanks in advance for any clarification about this.