stdio optimizations include the prevention of 'doubly opening' a file. If a file is opened that is already opened, the file handle is duplicated instead of using the normal fopen call.
git-svn-id: https://vgmstream.svn.sourceforge.net/svnroot/vgmstream@180 51a99a44-fe44-0410-b1ba-c3e57ba2b86b