IF col = 0, return true  when col IS NULL

How to reproduce:
(version 19.9.2)
```
CREATE TABLE default.test (ne UInt64,test Nullable(Float64)) ENGINE = MergeTree() PRIMARY KEY (ne) ORDER BY (ne);
INSERT INTO default.test VALUES (1,NULL);

SELECT IF(test = 0,1,0) FROM default.test
=> 1 expected 0
```

Can we do differently?
