**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))



const Names & required_result_column_names_ = Names{});
    
    InterpreterSelectQuery(
        const ASTPtr & query_ptr_,
        ContextPtr context_,
        const BlockInputStreamPtr & input_,
        const SelectQueryOptions & = {});
    
    InterpreterSelectQuery(
        const ASTPtr & query_ptr_,
        ContextPtr context_,
        Pipe input_pipe_,
        const SelectQueryOptions & = {});
    
    InterpreterSelectQuery(
        const ASTPtr & query_ptr_,
        ContextPtr context_,
        const StoragePtr & storage_,
        const StorageMetadataPtr & metadata_snapshot_ = nullptr,
        const SelectQueryOptions & = {});
    ~InterpreterSelectQuery() override;
    
    BlockIO execute() override;
    
    virtual void buildQueryPlan(QueryPlan & query_plan) override;
    bool ignoreLimits() const override { return options.ignore_limits; }
    bool ignoreQuota() const override { return options.ignore_quota; }
    virtual void ignoreWithTotals() override;
    ASTPtr getQuery() const { return query_ptr; }
    const SelectQueryInfo & getQueryInfo() const { return query_info; }