backport r6467 from trunk

git-svn-id: https://svn.code.sf.net/p/mingw-w64/code@6468 4407c894-4637-0410-b4f5-ada5f102cad1
Add secapi wrapper for sprintf_s

git-svn-id: https://svn.code.sf.net/p/mingw-w64/code@6469 4407c894-4637-0410-b4f5-ada5f102cad1