*: parser subpartition option for 'partition by range columns'

[tiancaiamao]

What problem does this PR solve?

Parse

mysql> create table t1 (a varchar(5), b int signed, c varchar(10), d datetime)
    -> partition by range columns(b,c)
    -> subpartition by hash(to_seconds(d))
    -> ( partition p0 values less than (2, 'b'),
    -> partition p1 values less than (4, 'd'),
    -> partition p2 values less than (10, 'za'));
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your TiDB version for the right syntax to use line 3 column 13 near "subpartition by hash(to_seconds(d))
( partition p0 values less than (2, 'b'),
partition p1 values less than (4, 'd'),
partition p2 values less than (10, 'za'))"

What is changed and how it works?

Parse subpartition and ignore it for 'partition by range columns'

Check List

Tests

• Unit test

[tiancaiamao]

PTAL @lysu @jackysp

[jackysp]

LGTM

[lysu]

LGTM

[lysu]

@tiancaiamao please fix ci "unrecognized import path "golang.org/x/oauth2""