Ruby » Ruby master

• io.c (rb_cloexec_fcntl_dupfd): get rid of compile error on windows.
  reported by Donovan Lampa at [ruby-core:43152] [Backport #6127],
  based on a patch by Hiroshi Shirosaki at [ruby-core:47917].

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_3@37150 b2dd03c8-39d4-4d8f-98ff-823fe69b080e