**How to reproduce**

CH version: `20.5.2 revision 54435` (latest on `apt` at the moment). Cannot reproduce on `20.4.5`, so it's a regression.

Table:

```sql
create table repro_hits (
    date Date,
    metric Float64
) engine=MergeTree() order by date
```

Query:

```sql
SELECT
    date as period,
    1 as having_check,
    min(date) as period_start,
    addDays(max(date), 1) as period_end,
    dateDiff('second', period_start, period_end) as total_duration,
    sum(metric) as metric_
FROM repro_hits
GROUP BY period
having having_check != -1
```

**Error message and/or stacktrace**
```
Received exception from server (version 20.5.2):
Code: 179. DB::Exception: Received from localhost:9000. DB::Exception: Different expressions with the same alias period_start:
min(date) AS period_start
and
date AS period_start
.
```

The error goes away if I opt out of optimization with `SETTINGS enable_optimize_predicate_expression = 0`.
{
    const FunctionFactory & function_factory = FunctionFactory::instance();
    if (!select_query->groupBy())
    {
        
        if (select_query->having())
            appendUnusedGroupByColumn(select_query, source_columns);
        return;
    }
    const auto is_literal = [] (const ASTPtr & ast) -> bool
    {
        return ast->as<ASTLiteral>();
    };
    auto & group_exprs = select_query->groupBy()->children;
    
    const auto remove_expr_at_index = [&group_exprs] (const size_t idx)
    {
        if (idx < group_exprs.size() - 1)
            std::swap(group_exprs[idx], group_exprs.back());
        group_exprs.pop_back();
    };
    
    for (size_t i = 0; i < group_exprs.size();)
    {
        if (const auto * function = group_exprs[i]->as<ASTFunction>())
        {
            
            if (possibly_injective_function_names.count(function->name))
            {