merge revision(s) r45046,r45047,r45063,r45087,r45146,r45150,r45151,r45152: [Backport #9525]

	* ext/socket: Wrap struct addrinfo by struct rb_addrinfo.

	* ext/socket: Bypass getaddrinfo() if node and serv are numeric.
	  Reporeted by Naotoshi Seo.  [ruby-core:60801] [Bug #9525]

	* ext/socket/extconf.rb: Detect struct sockaddr_in6.sin6_len.

	* ext/socket/sockport.h (SET_SIN6_LEN): New macro.
	  (INIT_SOCKADDR_IN6): Ditto.

	* ext/socket/rubysocket.h (struct rb_addrinfo): Add
	  allocated_by_malloc field.

	* ext/socket/raddrinfo.c (numeric_getaddrinfo): New function.
	  (rb_getaddrinfo): Call numeric_getaddrinfo at first.
	  (rb_freeaddrinfo): Free struct addrinfo properly when it is
	  allocated by numeric_getaddrinfo.

	* ext/socket/raddrinfo.c (numeric_getaddrinfo): Use xcalloc.
	  Suggested by Eric Wong.
	  https://bugs.ruby-lang.org/issues/9525#note-14

	* ext/socket/raddrinfo.c (rb_getaddrinfo): second argument of
	  MEMZERO is type.  Coverity Scan found this bug.

	* include/ruby/win32.h, win32/win32.c (rb_w32_inet_pton): add a
	  wrapper function for inet_pton minimum supported client is
	  Vista, as well as inet_ntop.

	* ext/socket/option.c (inet_pton): use rb_w32_inet_pton, instead of
	  inet_ntop directly, which is unavailable on older version Windows.

	* ext/socket/raddrinfo.c (inet_pton): use rb_w32_inet_pton, instead of
	  inet_pton directly, which is unavailable on older version Windows.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_1@47415 b2dd03c8-39d4-4d8f-98ff-823fe69b080e