* ext/socket/init.c (cloexec_accept): Fix a compile error on
  Debian GNU/kFreeBSD.  Consider HAVE_ACCEPT4 is defined
  but SOCK_CLOEXEC is not defined.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@40136 b2dd03c8-39d4-4d8f-98ff-823fe69b080e