WinStoreCompat: fix declaration and behaviour of SleepEx

git-svn-id: https://mingw-w64.svn.sourceforge.net/svnroot/mingw-w64/trunk@5857 4407c894-4637-0410-b4f5-ada5f102cad1
WinStoreCompat: Add Tls replacement functions using Fls*

git-svn-id: https://mingw-w64.svn.sourceforge.net/svnroot/mingw-w64/trunk@5858 4407c894-4637-0410-b4f5-ada5f102cad1
WinStoreCompat: put WINAPI inside the ( for better compatibility

git-svn-id: https://mingw-w64.svn.sourceforge.net/svnroot/mingw-w64/trunk@5859 4407c894-4637-0410-b4f5-ada5f102cad1