Use POCL_CACHE_DIR instead of writableHome...Hook

test/compilers/opencl-run.nix

@@ -1,31 +0,0 @@
-{
-  stdenv,
-  clang-ompss2,
-  nanos6,
-}:
-
-stdenv.mkDerivation {
-  version = "0.0.1";
-  name = "test-clang-ompss2";
-  src = ./.;
-  buildInputs = [
-    clang-ompss2
-    nanos6
-  ];
-
-  env = {
-    # NIX_DEBUG = 1;
-    OCL_ICD_VENDORS = "";
-  };
-
-  buildPhase = ''
-    clang -fompss-2 hello.c -o hello
-    ./hello
-    clang++ -fompss-2 hello.cc -o hello
-    ./hello
-  '';
-
-  installPhase = ''
-    mkdir -p $out
-  '';
-}