Re-introduce opencl.kernels usage for LLVM 3.6
Re-introduce opencl.kernels usage for LLVM 3.6

mpflanzer/Oclgrind,mpflanzer/Oclgrind,surround-io/oclgrind,surround-io/oclgrind,mpflanzer/Oclgrind,surround-io/oclgrind,surround-io/oclgrind,mpflanzer/Oclgrind