Support local sockets with inet:i/0

Before:

1> gen_udp:open(0, [local, {ip, {local, "unixdomainfile"}}]).
{ok,#Port<0.6>}
2> inet:i().
** exception error: bad argument
     in function  integer_to_list/1
        called as integer_to_list(<<"unixdomainfile">>)
     in call from inet:fmt_port/2 (inet.erl, line 1646)
     in call from inet:fmt_addr/2 (inet.erl, line 1642)
     in call from inet:'-i_line/3-lc$^0/1-0-'/3 (inet.erl, line 1547)
     in call from inet:'-i_line/3-lc$^0/1-0-'/3 (inet.erl, line 1547)
     in call from inet:'-info_lines/3-lc$^0/1-0-'/3 (inet.erl, line 1546)
     in call from inet:ii/3 (inet.erl, line 1531)
     in call from inet:i/0 (inet.erl, line 1515)

After:

Port Module    Recv Sent Owner      Local Address           Foreign Address State Type
4160 local_udp 0    0    <0.1747.0> local:unixdomainfile    *:*             IDLE  DGRAM

0 files changed, 0 insertions, 0 deletions