uniq: support -z

function                                             old     new   delta
uniq_main                                            391     427     +36
packed_usage                                       33570   33549     -21
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(add/remove: 0/0 grow/shrink: 1/1 up/down: 36/-21)             Total: 15 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
3 files changed