buildMozillaMach: remove apple-sdk_15 hack for fileport.h (#468742)

    # linking firefox hits the vm.max_map_count kernel limit with the default musl allocator

    # TODO: Default vm.max_map_count has been increased, retest without this

    export LD_PRELOAD=${mimalloc}/lib/libmimalloc.so

  ''

  +

    # fileport.h was exposed in SDK 15.4 but we have only 15.2 in nixpkgs so far.

    lib.optionalString

      (

        stdenv.hostPlatform.isDarwin

        && lib.versionAtLeast version "143"

        && lib.versionOlder version "145"

        && lib.versionOlder apple-sdk_15.version "15.4"

      )

      ''

        mkdir -p xnu/sys

        cp ${apple-sdk_15.sourceRelease "xnu"}/bsd/sys/fileport.h xnu/sys

        export CXXFLAGS="-isystem $(pwd)/xnu"

  '';

  # firefox has a different definition of configurePlatforms from nixpkgs, see configureFlags