* path.cc (is_floppy): Make externally available.

* path.h (is_floppy): Declare.
	* syscalls.cc (sync): Check for floppies on A: and B: in guid case.
	Don't call setmntent in non-guid case but evaluate drive bit mask
	locally.

winsup/cygwin/path.cc

@@ -2478,7 +2478,7 @@ cygwin_umount (const char *path, unsigned flags)
   return res;
 }
 
-static bool
+bool
 is_floppy (const char *dos)
 {
   char dev[256];