regression: str_to_date() cannot be used in the CHECK clause

The following table can be created under 12.2.2, but not 12.3.2.
```
--------------
CREATE TABLE observation(
id INT NOT NULL PRIMARY KEY AUTO_INCREMENT,
serial VARCHAR(20) NOT NULL,
observation_date DATE NOT NULL,

CONSTRAINT CHECK(observation_date >= (str_to_date(substr(serial, 6, 7), '%Y%j')))
)
--------------

ERROR 1901 (HY000) at line 3: Function or expression 'str_to_date()' cannot be used in the CHECK clause of `CONSTRAINT_1`
```