[parser] parser: append replica-only state to previous one strictly (p…

…ingcap#952)

parser/model/model.go

@@ -36,14 +36,17 @@ const (
 	// StateWriteOnly means we can use any write operation on this schema element,
 	// but outer can't read the changed data.
 	StateWriteOnly
-	// StateReplica means we're waiting tiflash replica to be finished.
-	StateReplicaOnly
 	// StateWriteReorganization means we are re-organizing whole data after write only state.
 	StateWriteReorganization
 	// StateDeleteReorganization means we are re-organizing whole data after delete only state.
 	StateDeleteReorganization
 	// StatePublic means this schema element is ok for all write and read operations.
 	StatePublic
+	// StateReplica means we're waiting tiflash replica to be finished.
+	StateReplicaOnly
+	/*
+	 *  Please add the new state at the end to keep the values consistent across versions.
+	 */
 )
 
 // String implements fmt.Stringer interface.