TCPSocket.gethostbyname has problems similar to
Socket.gethostbyname.
An example of the problem which only the address family of
the first address is returned:
```
pp TCPSocket.gethostbyname("www.wide.ad.jp")
#=> ["www.wide.ad.jp",
[],
10,
"2001:200:dff:fff1:216:3eff:fe4b:651c",
"203.178.137.58"]
```
The address family of the first address, AF_INET6 (10), is
returned but
the address family of the second address, AF_INET, is not
returned.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@60319 b2dd03c8-39d4-4d8f-98ff-823fe69b080e