darwin.binutils: fix wrapper of as when cross-compiling to aarch64-darwin (#134097)

pkgs/os-specific/darwin/binutils/default.nix

@@ -56,8 +56,8 @@ stdenv.mkDerivation {
   # and using clang directly here is a better option than relying on cctools.
   # On x86_64-darwin the Clang version is too old to support this mode.
   + lib.optionalString stdenv.isAarch64 ''
-    rm $out/bin/as
-    makeWrapper "${clang-unwrapped}/bin/clang" "$out/bin/as" \
+    rm $out/bin/${targetPrefix}as
+    makeWrapper "${clang-unwrapped}/bin/clang" "$out/bin/${targetPrefix}as" \
       --add-flags "-x assembler -integrated-as -c"
   '';