Abort is triggered in debug build due to logical error.

```
CREATE TABLE A(k UInt32, t UInt32, a UInt64) ENGINE = MergeTree() ORDER BY (k, t);
INSERT INTO A(k,t,a) VALUES (1,101,1),(1,102,2),(1,103,3),(1,104,4),(1,105,5);

CREATE TABLE B(k UInt32, t UInt32, b UInt64) ENGINE = MergeTree() ORDER BY (k, t);
INSERT INTO B(k,t,b) VALUES (1,102,2), (1,104,4);

SELECT 
    (257, NULL, NULL), 
    (1, -2), 
    (-2, 7), 
    ('102.5', '0.03', NULL, NULL, NULL), 
    A.k, 
    toString((10, 0), 10.000100135803223), 
    A.a, 
    B.b, 
    toString(B.t), 
    B.k
FROM A
ASOF INNER JOIN B ON (A.k = B.k) AND NULL AND greaterOrEquals(B.t)
ORDER BY tuple(A.k) ASC;


Received exception from server (version 20.7.1):
Code: 1001. DB::Exception: Received from localhost:9000. DB::Exception: St12out_of_range: vector. 
```

{
    if (const auto * ident = ast->as<ASTIdentifier>())
    {
        if (IdentifierSemantic::getColumnName(*ident))
            out.push_back(ident);
        return;
    }
    for (const auto & child : ast->children)
        getIdentifiers(child, out);
}
std::pair<size_t, size_t> CollectJoinOnKeysMatcher::getTableNumbers(const ASTPtr & expr, const ASTPtr & left_ast, const ASTPtr & right_ast,
                                                                    Data & data)
{
    std::vector<const ASTIdentifier *> left_identifiers;
    std::vector<const ASTIdentifier *> right_identifiers;
    getIdentifiers(left_ast, left_identifiers);
    getIdentifiers(right_ast, right_identifiers);
    size_t left_idents_table = getTableForIdentifiers(left_identifiers, data);
    size_t right_idents_table = getTableForIdentifiers(right_identifiers, data);
    if (left_idents_table && left_idents_table == right_idents_table)
    {
        auto left_name = queryToString(*left_identifiers[0]);
        auto right_name = queryToString(*right_identifiers[0]);
        throwSyntaxException("In expression " + queryToString(expr) + " columns " + left_name + " and " + right_name
                                + " are from the same table but from different arguments of equal function.");
    }
    return std::make_pair(left_idents_table, right_idents_table);
}
const ASTIdentifier * CollectJoinOnKeysMatcher::unrollAliases(const ASTIdentifier * identifier, const Aliases & aliases)