xfs: implement extended feature masks

The version 5 superblock has extended feature masks for compatible,
incompatible and read-only compatible feature sets. Implement the
masking and mount-time checking for these feature masks.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

diff --cc fs/xfs/xfs_log_recover.c
Simple merge

diff --cc fs/xfs/xfs_mount.c
Simple merge

diff --cc fs/xfs/xfs_sb.h
Simple merge