scripts/functions: extract: portable call for old and defective tars

Instead of using -J, --lzma, --use-compress-program or the like
use <compressor> -dc <file> | tar -f -

Signed-off-by: Titus von Boxberg <titus@v9g.de>
(transplanted from 49af7802dcd538ec3cb64337030b03ac2c6344d2)

#!/bin/sh

call_to=@@DEFAULT_LD@@

case "${CTNG_LD_IS}" in

    bfd)    call_to=bfd;;

    gold)   call_to=gold;;

esac

exec "${0}.${call_to}" "$@"

exit $?