RANGE frame clause in window function not alway needs a ORDER clause

[winoros]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. What did you do?
   If possible, provide a recipe for reproducing the error.

CREATE TABLE t1(a INT, b CHAR(1), c DATETIME, d BLOB);
INSERT INTO t1 VALUES (1,'x','2010-01-01','blob'), (2, 'y', '2011-01-01', ''),
(3, 'y', '2012-01-01', ''), (4, 't', '2012-01-01', 'blob'),
(5, null, '2013-01-01', null);

SELECT a, b, c, SUM(a) OVER
(RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW)
FROM t1;

2. What did you expect to see?

execute successfully.

3. What did you see instead?

Panicked.

4. What version of TiDB are you using (tidb-server -V or run select tidb_version(); on TiDB)?