**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))



: ExpressionAnalyzer(query_, syntax_analyzer_result_, context_, 0, false, {}, {})
    {
    }
    ~ExpressionAnalyzer();
    void appendExpression(ExpressionActionsChain & chain, const ASTPtr & expr, bool only_types);
    
    
    
    
    ActionsDAGPtr getActionsDAG(bool add_aliases, bool project_result = true);
    ExpressionActionsPtr getActions(bool add_aliases, bool project_result = true, CompileExpressions compile_expressions = CompileExpressions::no);
    
    
    ExpressionActionsPtr getConstActions(const ColumnsWithTypeAndName & constant_inputs = {});
    /** Sets that require a subquery to be create.
      * Only the sets needed to perform actions returned from already executed `append*` or `getActions`.
      * That is, you need to call getSetsWithSubqueries after all calls of `append*` or `getActions`
      *  and create all the returned sets before performing the actions.
      */
    SubqueriesForSets & getSubqueriesForSets() { return subqueries_for_sets; }
    PreparedSets & getPreparedSets() { return prepared_sets; }