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)).
```

{
    Node node;
    node.type = ActionType::ALIAS;
    node.result_type = child.result_type;
    node.result_name = std::move(alias);
    node.column = child.column;
    node.children.emplace_back(&child);
    return addNode(std::move(node));
}
const ActionsDAG::Node & ActionsDAG::addArrayJoin(const Node & child, std::string result_name)
{
    const DataTypeArray * array_type = typeid_cast<const DataTypeArray *>(child.result_type.get());
    if (!array_type)
        throw Exception("ARRAY JOIN requires array argument", ErrorCodes::TYPE_MISMATCH);
    Node node;
    node.type = ActionType::ARRAY_JOIN;
    node.result_type = array_type->getNestedType();
    node.result_name = std::move(result_name);
    node.children.emplace_back(&child);
    return addNode(std::move(node));
}
const ActionsDAG::Node & ActionsDAG::addFunction(