**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))



auto it = window_descriptions.find(function_node->window_name);
            if (it == std::end(window_descriptions))
            {
                throw Exception(ErrorCodes::UNKNOWN_IDENTIFIER,
                    "Window '{}' is not defined (referenced by '{}')",
                    function_node->window_name,
                    function_node->formatForErrorMessage());
            }
            it->second.window_functions.push_back(window_function);
        }
        else
        {
            const auto & definition = function_node->window_definition->as<
                const ASTWindowDefinition &>();
            WindowDescription desc;
            desc.window_name = definition.getDefaultWindowName();
            makeWindowDescriptionFromAST(*getContext(), window_descriptions,
                desc, &definition);
            auto [it, inserted] = window_descriptions.insert(
                {desc.window_name, desc});
            if (!inserted)
            {
                assert(it->second.full_sort_description
                    == desc.full_sort_description);
            }
            it->second.window_functions.push_back(window_function);
        }
    }
}
const ASTSelectQuery * ExpressionAnalyzer::getSelectQuery() const