**Usage**
Postgres, MySQL, and Oracle support the expression `LEFT JOIN ... ON 1 = 1`, but ClickHouse does not.

It may be possible to replace `LEFT JOIN ... ON 1 = 1` with `CROSS JOIN`, but I want to use the query in the same form for lots of databases.

Please support the expression `LEFT JOIN ... ON 1 = 1`.


**Detailed SQL**
```SQL
CREATE TABLE test
(
    `name` Nullable(String),
    `id` int
)
ENGINE = Log();

insert into test values ('a', 1) ('b', 2) (null, 3);

select * from test t1 left join (select * from test ) t2 on 1 = 1   
-- DB::Exception: Not equi-join ON expression: 1 = 1. No columns in one of equality side.: While processing 1 = 1.
```

{
    ASTs & elements = select_query->select()->children;
    std::map<String, size_t> required_columns_with_duplicate_count;
    if (!required_result_columns.empty())
    {
        
        for (const auto & name : required_result_columns)
        {
            if (remove_dups)
                required_columns_with_duplicate_count[name] = 1;
            else
                ++required_columns_with_duplicate_count[name];
        }
    }
    else if (remove_dups)
    {
        
        for (const auto & elem : elements)
            required_columns_with_duplicate_count.emplace(elem->getAliasOrColumnName(), 1);