llvmPackages: Organize files

Always do pkg/default.nix not pkg.nix; use directories to avoid
prefixing patches and other files.

pkgs/development/compilers/llvm/rocm/lld/default.nix

@@ -0,0 +1,37 @@
+{ lib, stdenv
+, cmake
+, libxml2
+, llvm
+
+, version
+, src
+}:
+
+stdenv.mkDerivation rec {
+  inherit version src;
+
+  pname = "lld";
+
+  nativeBuildInputs = [ cmake ];
+
+  buildInputs = [ libxml2 llvm ];
+
+  outputs = [ "out" "dev" ];
+
+  postInstall = ''
+    moveToOutput include "$dev"
+    moveToOutput lib "$dev"
+
+    # Fix lld binary path for CMake.
+    substituteInPlace "$dev/lib/cmake/lld/LLDTargets-release.cmake" \
+      --replace "\''${_IMPORT_PREFIX}/bin/lld" "$out/bin/lld"
+  '';
+
+  meta = with lib; {
+    description = "ROCm fork of the LLVM Linker";
+    homepage = "https://github.com/RadeonOpenCompute/llvm-project";
+    license = licenses.ncsa;
+    maintainers = with maintainers; [ danieldk ];
+    platforms = platforms.linux;
+  };
+}