cc/gcc: fix gcc 4.8 build for C library without threads support

Signed-off-by: Niels Penneman <niels@penneman.org>
Message-Id: <309df93f4354c80e05c9.1388743085@i7sb.local>
Patchwork-Id: 306521

# Compute s390-specific values

CT_DoArchTupleValues() {

    # That's the only thing to override

    if [ "${CT_ARCH_64}" = "y" ]; then

        CT_TARGET_ARCH="s390x${CT_ARCH_SUFFIX}"

    fi

}