**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.
```

ASOF::Inequality getAsofInequality() { return asof_inequality; }
    ASTPtr leftKeysList() const;
    ASTPtr rightKeysList() const; 
    const NamesAndTypesList & columnsFromJoinedTable() const { return columns_from_joined_table; }
    Names columnsAddedByJoin() const
    {
        Names res;
        for (const auto & col : columns_added_by_join)
            res.push_back(col.name);
        return res;
    }
    
    void setRightKeys(const Names & keys) { getOnlyClause().key_names_right = keys; }
    Block getRequiredRightKeys(const Block & right_table_keys, std::vector<String> & keys_sources) const;
    String renamedRightColumnName(const String & name) const;
    std::unordered_map<String, String> leftToRightKeyRemap() const;
    void setStorageJoin(std::shared_ptr<StorageJoin> storage);
    void setStorageJoin(std::shared_ptr<StorageDictionary> storage);
    std::shared_ptr<StorageJoin> getStorageJoin() { return right_storage_join; }
    bool tryInitDictJoin(const Block & sample_block, ContextPtr context);
    bool isSpecialStorage() const { return right_storage_dictionary || right_storage_join; }
    const DictionaryReader * getDictionaryReader() const { return dictionary_reader.get(); }
};
}