Tor unit tests fail on FreeBSD IPv6-only

address/get_if_addrs_ifaddrs: [forking] 
  FAIL src/test/test_address.c:272: assert(smartlist_contains_localhost_tor_addr(results))
  [get_if_addrs_ifaddrs FAILED]
address/ifaddrs_to_smartlist: OK
address/get_if_addrs_ioctl: [forking] Nov 18 09:35:23.398 [err] socket failed: Protocol not supported

  FAIL src/test/test_address.c:484: assert(result)
  [get_if_addrs_ioctl FAILED]
…
util/socket: [forking] 
  FAIL src/test/test_util.c:4360: assert(SOCKET_OK(fd1))
  [socket FAILED]
util/socketpair: [forking] OK
util/socketpair_ersatz: [forking] 
  FAIL src/test/test_util.c:4416: assert(0 OP_EQ tor_socketpair_fn(family, SOCK_STREAM, 0, fds)): 0 vs -43
  [socketpair_ersatz FAILED]