xfs: move ftype conversion functions to libxfs

These functions are needed in userspace for repair and mkfs to
do the right thing. Move them to libxfs so they can be easily
shared.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>

fs/xfs/libxfs/xfs_dir2.h

@@ -31,6 +31,12 @@ struct xfs_dir2_data_unused;
 
 extern struct xfs_name	xfs_name_dotdot;
 
+/*
+ * directory filetype conversion tables.
+ */
+#define S_SHIFT 12
+extern const unsigned char xfs_mode_to_ftype[];
+
 /*
  * directory operations vector for encode/decode routines
  */