Fails with unparenthesized comparison as `IN` left operand (MariaDB)

[laowantong]

Database Engine MariaDB (and presumably MySQL).

To Reproduce

import pkg from 'node-sql-parser';
const { Parser } = pkg;
const parser = new Parser();

parser.parse("SELECT * FROM T1 WHERE a = b IN (SELECT flag FROM T2)");

• node-sql-parser: 5.3.9
• node: v18.12.0

Expected behavior
This statement is valid SQL for MySQL and MariaDB, and should not fail to parse.

Additional context
Works fine with parenthesis: SELECT * FROM T1 WHERE (a = b) IN (SELECT flag FROM T2)