[FEATURE] MERGE ON without () #1880

Grammar or Syntax Description

Hello, when I use JSqlParser to parse 'MERGE' statement and there are missing parentheses after 'ON,' it throws an error.

SQL Example

merge into table1 USING ( select * from table2) c on table1.aa=c.aa WHEN NOT MATCHED THEN INSERT ( bb,aa ) VALUES (c.aa, c.bb ,c.cc)