pocl: migrate to lib.cmakeBool and lib.cmakeFeature

  cmakeFlags =

    [

      # avoid the runtime linker pulling in a different llvm e.g. from graphics drivers

      "-DSTATIC_LLVM=ON"

      "-DENABLE_POCL_BUILDING=OFF"

      "-DPOCL_ICD_ABSOLUTE_PATH=ON"

      "-DENABLE_ICD=ON"

      "-DCLANG=${clangWrapped}/bin/clang"

      "-DCLANGXX=${clangWrapped}/bin/clang++"

      "-DENABLE_REMOTE_CLIENT=ON"

      "-DENABLE_REMOTE_SERVER=ON"

      (lib.cmakeBool "STATIC_LLVM" true)

      (lib.cmakeBool "ENABLE_POCL_BUILDING" false)

      (lib.cmakeBool "POCL_ICD_ABSOLUTE_PATH" true)

      (lib.cmakeBool "ENABLE_ICD" true)

      (lib.cmakeBool "ENABLE_REMOTE_CLIENT" true)

      (lib.cmakeBool "ENABLE_REMOTE_SERVER" true)

      (lib.cmakeFeature "CLANG" "${clangWrapped}/bin/clang")

      (lib.cmakeFeature "CLANGXX" "${clangWrapped}/bin/clang++")

    ]

    # Only x86_64 supports "distro" which allows runtime detection of SSE/AVX

    ++ lib.optionals stdenv.hostPlatform.isx86_64 [

      "-DKERNELLIB_HOST_CPU_VARIANTS=distro"

      (lib.cmakeFeature "KERNELLIB_HOST_CPU_VARIANTS" "distro")

    ]

    ++ lib.optionals (!stdenv.hostPlatform.isx86_64) [

      "-DLLC_HOST_CPU=generic"

      (lib.cmakeFeature "LLC_HOST_CPU" "generic")

    ];

  nativeBuildInputs = [