**How to reproduce**
Clickhouse version 21.2-21.3

```
SELECT x
FROM
(
    SELECT 1 AS x
    UNION DISTINCT
    SELECT 1
)
LIMIT 1

Query id: b82bbb8d-dea9-4f1c-9a2f-5b0e9b6c2422


0 rows in set. Elapsed: 0.002 sec.

Received exception from server (version 21.2.3):
Code: 49. DB::Exception: Received from localhost:9000. DB::Exception: Bad cast from type DB::ASTSelectWithUnionQuery to DB::ASTSelectQuery.
```


const auto & table_name = table_id.getTableName();
    
    ASTPtr query_ast = std::make_shared<ASTSelectQuery>();
    auto * select_ast = query_ast->as<ASTSelectQuery>();
    select_ast->setExpression(ASTSelectQuery::Expression::SELECT, std::make_shared<ASTExpressionList>());
    auto expr_list = select_ast->select();
    
    expr_list->children.push_back(row_policy_filter);
    
    for (const auto & column_str : prerequisite_columns)
    {
        ParserExpression expr_parser;
        expr_list->children.push_back(parseQuery(expr_parser, column_str, 0, context->getSettingsRef().max_parser_depth));
    }
    select_ast->setExpression(ASTSelectQuery::Expression::TABLES, std::make_shared<ASTTablesInSelectQuery>());
    auto tables = select_ast->tables();
    auto tables_elem = std::make_shared<ASTTablesInSelectQueryElement>();
    auto table_expr = std::make_shared<ASTTableExpression>();
    tables->children.push_back(tables_elem);
    tables_elem->table_expression = table_expr;
    tables_elem->children.push_back(table_expr);
    table_expr->database_and_table_name = createTableIdentifier(db_name, table_name);
    table_expr->children.push_back(table_expr->database_and_table_name);
    
    auto syntax_result = TreeRewriter(*context).analyzeSelect(query_ast, TreeRewriterResult({}, storage, metadata_snapshot));
    SelectQueryExpressionAnalyzer analyzer(query_ast, syntax_result, *context, metadata_snapshot);
    actions = analyzer.simpleSelectActions();
    return expr_list->children.at(0)->getColumnName();
}
InterpreterSelectQuery::InterpreterSelectQuery(