io.c: reopen OS encoding path
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@51069 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
io.c: reopen OS encoding path
[ruby-core:69780] [Bug #11320]
use _wfreopen_s() if available.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@51069 b2dd03c8-39d4-4d8f-98ff-823fe69b080e