You have to provide the following information whenever possible.

**Describe the bug**
This query fails with the latest stable version 21.5.5.12. It worked with the last stable version 21.4.7.3.

**Does it reproduce on recent release?**
yes

**How to reproduce**
21.5.5.12

```
SELECT
    label,
    number
FROM
(
    SELECT
        'a' AS label,
        number
    FROM
    (
        SELECT number
        FROM numbers(10)
    )
    UNION ALL
    SELECT
        'b' AS label,
        number
    FROM
    (
        SELECT number
        FROM numbers(10)
    )
)
WHERE number IN
(
    SELECT number
    FROM numbers(5)
)
```

**Expected behavior**
Query should run without errors

**Error message and/or stacktrace**
```
Received exception from server (version 21.5.5):
Code: 49. DB::Exception: Received from localhost:9000. DB::Exception: Block structure mismatch in Pipe::unitePipes stream: different names of columns:
label String String(size = 0), number UInt64 UInt64(size = 0), 'b' String Const(size = 0, String(size = 1))
label String String(size = 0), number UInt64 UInt64(size = 0), 'a' String Const(size = 0, String(size = 1)).
```

{
    std::unordered_set<const Node *> visited_nodes;
    std::stack<Node *> stack;
    for (const auto * node : index)
    {
        visited_nodes.insert(node);
        stack.push(const_cast<Node *>(node));
    }
    for (auto & node : nodes)
    {
        
        bool is_array_join = node.type == ActionType::ARRAY_JOIN;
        if (is_array_join && visited_nodes.count(&node) == 0)
        {
            visited_nodes.insert(&node);
            stack.push(&node);
        }
        if (node.type == ActionType::INPUT && !allow_remove_inputs)
            visited_nodes.insert(&node);
    }
    while (!stack.empty())
    {
        auto * node = stack.top();
        stack.pop();
        if (!node->children.empty() && node->column && isColumnConst(*node->column))
        {
            
            node->type = ActionsDAG::ActionType::COLUMN;
            node->children.clear();
        }