__metadata should register function that returns type instead of literal type

Imagine case with circular dependencies

class Car {
  @Field owner: Person // !!! Error: Person is not defined.
}

class Person {
  @Field car: Car;
}

// car has owner, owner has car

Typescript metadata would be emitted here like

eg.
__metadata('design:type', Person).

As Person is injected for the first time before Person class is initialized, it will result with ReferenceError saying Person is not defined.

If it'd emit metadata like:
__metadata('design:type', () => Person)

it'd be fine.

Later on, when using Reflect.metadata, it would also need to call meta function instead of just returning the type.

If you think it's good idea, do you have any suggestions about starting point for PR that would implement this change?

Empieza rastreando la ruta del compilador de TypeScript que emite metadatos de decoradores y, después, inspecciona cómo Reflect.metadata consume el valor emitido. Se considera terminado cuando el ejemplo circular Car/Person evita el ReferenceError de inicialización y los consumidores de metadatos invocan la función de tipo diferida; el payload no menciona archivos ni tests.