How to access `llvm-as` to define symlink

1

I have the following flake.nix, but I cannot access the llvm-as correctly to define a symlink to the version:

{
  nixConfig = {
    substituters = [
      # Add here some other mirror if needed.
      "https://cache.nixos.org/"
    ];
    extra-substituters = [
      # Nix community's cache server
      "https://nix-community.cachix.org"
    ];
    extra-trusted-public-keys = [
      "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
    ];
  };

  inputs = {
    # Nixpkgs
    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";

    # You can access packages and modules from different nixpkgs revs
    # at the same time. Here's an working example:
    nixpkgsStable.url = "github:nixos/nixpkgs/nixos-23.11";
    # Also see the 'stable-packages' overlay at 'overlays/default.nix'.

    flake-utils.url = "github:numtide/flake-utils";
  };

  outputs = {
    self,
    nixpkgs,
    nixpkgsStable,
    flake-utils,
    ...
  } @ inputs:
    flake-utils.lib.eachDefaultSystem
    # Creates an attribute map `{ devShells.<system>.default = ...}`
    # by calling this function:
    (
      system: let
        overlays = [];

        # Import nixpkgs and load it into pkgs.
        pkgs = import nixpkgs {
          inherit system overlays;
        };

        nodePackages = pkgs.callPackage ./tools/nix/node-packages/default.nix {};

        clangVersion = "16";
        llvmPkgs = pkgs."llvmPackages_${clangVersion}";

        compilerLinks = pkgs.runCommand "clang-links" {} ''
          mkdir -p $out/bin
          ln -s ${llvmPkgs.libstdcxxClang}/bin/clang $out/bin/clang-${clangVersion}
          ln -s ${llvmPkgs.libstdcxxClang}/bin/clang++ $out/bin/clang++-${clangVersion}

          #### THIS SYMLINK DOES NOT WORK, llvm-as is somewhere else but where?
          ln -s ${llvmPkgs.libstdcxxClang.bintools}/bin/llvm-as $out/bin/llvm-as-${clangVersion}
        '';

        buildInputs = with pkgs; [
          # C++
          llvmPkgs.bintools
          llvmPkgs.openmp
          llvmPkgs.lld
          llvmPkgs.llvm
          llvmPkgs.lldb
          # llvmPkgs.libclc
          llvmPkgs.libclang
          llvmPkgs.libllvm
          llvmPkgs.libcxx
          (hiPrio llvmPkgs.libstdcxxClang)

          compilerLinks
        ];
      in {
        devShells = {
          default = pkgs.mkShell {
            inherit buildInputs;
          };
        };
      }
    );
}

The symlink for llvm-as is wrong, but I do not know how to investigate, and fix these problems.
I tried searching with nix repl -f <nixpkgs> and pkgs.llvmPackages_16.libstdcxxClang.bintools.outPath etc.

Some hint would be very appreciated.