**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))



&& limit_length <= std::numeric_limits<UInt64>::max() - limit_offset
        && limit_length + limit_offset < max_block_size)
    {
        max_block_size = std::max(UInt64(1), limit_length + limit_offset);
        max_threads_execute_query = max_streams = 1;
    }
    if (!max_block_size)
        throw Exception("Setting 'max_block_size' cannot be zero", ErrorCodes::PARAMETER_OUT_OF_BOUND);
    
    if (query_plan.isInitialized())
    {
        
    }
    else if (interpreter_subquery)
    {
        
        
        if (required_columns.size() < source_header.columns())
        {
            ASTPtr subquery = extractTableExpression(query, 0);
            if (!subquery)
                throw Exception("Subquery expected", ErrorCodes::LOGICAL_ERROR);
            interpreter_subquery = std::make_unique<InterpreterSelectWithUnionQuery>(
                subquery, getSubqueryContext(context),
                options.copy().subquery().noModify(), required_columns);
            if (query_analyzer->hasAggregation())
                interpreter_subquery->ignoreWithTotals();
        }
        interpreter_subquery->buildQueryPlan(query_plan);
        query_plan.addInterpreterContext(context);