Spring Generate reflection hints for custom types that SpringConstraintValidatorFactory will instantiate

Affects: 6.0

This Spring Boot issue contains a sample application that's using Framework's @Validated and a custom constraint annotation that references a custom ConstraintValidator implementation. The annotation is used on a parameter of @GetMapping method. The ConstraintValidator implementation, IdValidator, is created by SpringConstraintValidatorFactory and this fails as it uses reflection.

It feels to me like Framework should be able to generate the necessary reflection hint automatically by following the trail of @Validated -> @Id -> IdValidator.

Comment From: sdeleuze

Duplicate of #29823.