pocl: add version 1.5 (#16455)
pocl: add version 1.5 (#16455)

* pocl: add version 1.5

* update clang version
LLNL/spack,iulian787/spack,LLNL/spack,iulian787/spack,iulian787/spack,LLNL/spack,iulian787/spack,LLNL/spack,LLNL/spack,iulian787/spack