[Doctrine] Support for query_builder in entity form field type

[Azenet]

Would it be possible to have the same autocompletion support that exists in entity repositories for this kind of thing :

class MyFormType extends AbstractType {
    public function buildForm(FormBuilderInterface $builder, array $options) {
        $builder
            ->add('field', 'entity', array(
                'class' => 'MyBundle:MyEntity',
                'query_builder' => function (EntityRepository $er) {
                    return $er->createQueryBuilder('e')
                        ->where('e.myField = :field')
                        ->setParameter('field', 'blah'); //setParameter already has completion from the where field
                }
            ));
    }
}