**Describe what's wrong**

Query with rollup using same selected field name as the name of underlying column reports structure mismatch

**Does it reproduce on recent release?**

yes

**How to reproduce**

`21.9.2.17`

```sql
CREATE TABLE test
(
    `d` DateTime,
    `a` LowCardinality(String),
    `b` UInt64
)
ENGINE = MergeTree
PARTITION BY toDate(d)
ORDER BY d;

SELECT *
FROM (
    SELECT
        a,
        max((d, b)).2 AS value
    FROM test
    GROUP BY rollup(a)
)
WHERE a <> '';
```

**Expected behavior**

This used to return an ok result on v21.8

**Error message and/or stacktrace**

> Code: 352. DB::Exception: Block structure mismatch in (columns with identical name must have identical structure) stream: different columns:
> notEquals(a, '') LowCardinality(UInt8) ColumnLowCardinality(size = 0, UInt8(size = 0), ColumnUnique(size = 1, UInt8(size = 1)))
> notEquals(a, '') LowCardinality(UInt8) Const(size = 0, ColumnLowCardinality(size = 1, UInt8(size = 1), ColumnUnique(size = 2, UInt8(size = 2)))). (AMBIGUOUS_COLUMN_NAME) (version 21.9.2.17 (official build))



{
    
    if (hasPrewhere())
    {
        auto check_actions = [](const ActionsDAGPtr & actions)
        {
            if (actions)
                for (const auto & node : actions->getNodes())
                    if (node.type == ActionsDAG::ActionType::ARRAY_JOIN)
                        throw Exception("PREWHERE cannot contain ARRAY JOIN action", ErrorCodes::ILLEGAL_PREWHERE);
        };
        check_actions(prewhere_info->prewhere_actions);
        check_actions(prewhere_info->alias_actions);
    }
}
std::string ExpressionAnalysisResult::dump() const
{
    WriteBufferFromOwnString ss;
    ss << "need_aggregate " << need_aggregate << "\n";
    ss << "has_order_by " << has_order_by << "\n";
    ss << "has_window " << has_window << "\n";
    if (before_array_join)
    {
        ss << "before_array_join " << before_array_join->dumpDAG() << "\n";
    }
    if (array_join)