**Describe the bug**

`sumIf` returns incorrect results in some cases with Nullable arguments.

**How to reproduce**

* Which ClickHouse server version to use
Latest master/arcadia version

* Queries to run that lead to unexpected result
```sql
:) select sumIf(toFloat64OrZero(b), a = 0) as r1, sumIf(cast(b as Float), a = 0) as r2, sum(if(a = 0, toFloat64OrZero(b), 0)) as r3 from (select arrayJoin([1, 2, 3, NULL]) as a, toNullable('10.0') as b)

SELECT
    sumIf(toFloat64OrZero(b), a = 0) AS r1,
    sumIf(CAST(b, 'Float'), a = 0) AS r2,
    sum(if(a = 0, toFloat64OrZero(b), 0)) AS r3
FROM
(
    SELECT
        arrayJoin([1, 2, 3, NULL]) AS a,
        toNullable('10.0') AS b
)

Query id: 2e4e320d-e52a-4514-bc6f-118485558191

┌─r1─┬─r2─┬─r3─┐
│ 10 │  0 │  0 │
└────┴────┴────┘
```
**Expected behavior**

All results are 0.

**Additional context**

It breaks when null values in Nullable column are compared with `assumeNotNull` from this column.
It also only breaks when first argument is Nullable too.


#include <AggregateFunctions/AggregateFunctionCombinatorFactory.h>
#include <AggregateFunctions/AggregateFunctionIf.h>
#include "AggregateFunctionNull.h"
namespace DB
{
namespace ErrorCodes
{
    extern const int LOGICAL_ERROR;
    extern const int ILLEGAL_TYPE_OF_ARGUMENT;
    extern const int NUMBER_OF_ARGUMENTS_DOESNT_MATCH;
}
class AggregateFunctionCombinatorIf final : public IAggregateFunctionCombinator