Autoconf: Print the GNU C Library version when needed in autogen.sh

[tcpdump] / tests / tcp_header_heapoverflow.out

    1  1995-08-15 05:27:12.999999 IP (tos 0x30, ttl 48, id 12336, offset 0, flags [none], proto TCP (6), length 12336, bad cksum 3030 (->69a8)!)
    48.48.48.48.12336 > 48.48.48.48.12336:  [|tcp]