**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.
```

class DictionaryReader;
namespace JoinStuff
{
class JoinUsedFlags
{
    using RawBlockPtr = const Block *;
    using UsedFlagsForBlock = std::vector<std::atomic_bool>;
    
    
    std::unordered_map<RawBlockPtr, UsedFlagsForBlock> flags;
    bool need_flags;
public:
    
    
    
    template <ASTTableJoin::Kind KIND, ASTTableJoin::Strictness STRICTNESS>
    void reinit(size_t size_);
    template <ASTTableJoin::Kind KIND, ASTTableJoin::Strictness STRICTNESS>
    void reinit(const Block * block_ptr);
    bool getUsedSafe(size_t i) const;
    bool getUsedSafe(const Block * block_ptr, size_t row_idx) const;
    template <bool use_flags, bool multiple_disjuncts, typename T>
    void setUsed(const T & f);
    template <bool use_flags, bool multiple_disjuncts, typename T>
    bool getUsed(const T & f);
    template <bool use_flags, bool multiple_disjuncts, typename T>
    bool setUsedOnce(const T & f);
};