Ruby » Ruby master

• io.c (io_fflush): remove fsync().
• io.c (rb_io_flush, rb_io_rewind): fsync() here.
  These pathces are backports of trunk r33651 for [Bug #5585]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_3@33658 b2dd03c8-39d4-4d8f-98ff-823fe69b080e