* io.c (rb_io_flush_raw, rb_io_fsync): [EXPERIMENTAL] remove force
  syncing for Win32 to speed up IO.  this may break some tests, and
  they'll be fixed later.
  [ruby-core:58570] [Bug #9153]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45254 b2dd03c8-39d4-4d8f-98ff-823fe69b080e