* ext/socket/extconf.rb: use all all tested available headers for
  have_func.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39256 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* 2013-02-16

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39257 b2dd03c8-39d4-4d8f-98ff-823fe69b080e