xen: replace `binutils-unwrapped` override with `binutils-unwrapped-all-targets` (#347001)

  OVMF,

  ipxe,

  checkpolicy,

  binutils-unwrapped,

  binutils-unwrapped-all-targets,

  # Documentation

  pandoc,

    lgpl21Only

    mit

    ;

  inherit (lib.meta) getExe;

  inherit (lib.meta) getExe';

  inherit (lib.lists)

    count

    flatten

    else

      [ ];

  ## Binutils Override ##

  # Originally, there were two versions of binutils being used: the standard one and

  # this patched one. Unfortunately, that required patches to the Xen Makefiles, and

  # quickly became too complex to maintain. The new solution is to simply build this

  # efi-binutils derivation and use it for the whole build process, except if

  # enableEFI is disabled; it'll then use `binutils`.

  efiBinutils = binutils-unwrapped.overrideAttrs (oldAttrs: {

    name = "efi-binutils";

    configureFlags = oldAttrs.configureFlags ++ [ "--enable-targets=x86_64-pep" ];

    doInstallCheck = false; # We get a spurious failure otherwise, due to a host/target mismatch.

    meta.mainProgram = "ld"; # We only really care for `ld`.

  });

  #TODO: fix paths instead.

  scriptEnvPath = makeSearchPathOutput "out" "bin" [

    bridge-utils

    ++ optionals withEFI [

      "EFI_VENDOR=${vendor}"

      "INSTALL_EFI_STRIP=1"

      "LD=${getExe efiBinutils}" # See the comment in the efiBinutils definition above.

      "LD=${getExe' binutils-unwrapped-all-targets "ld"}"

    ]

    # These flags set the CONFIG_* options in /boot/xen.config

    # and define if the default policy file is built. However,