self reference support for foreignkeys

test-data/typecheck/related_fields.test

@@ -213,4 +213,18 @@ reveal_type(Member().apps)  # E: Revealed type is 'django.db.models.manager.Rela
 from django.db import models
 class App(models.Model):
     pass
-[out]
+[out]
+
+[CASE foreign_key_with_self]
+from django.db import models
+class User(models.Model):
+    parent = models.ForeignKey('self', on_delete=models.CASCADE)
+reveal_type(User().parent)  # E: Revealed type is 'main.User*'
+[out]
+
+[CASE many_to_many_with_self]
+from django.db import models
+class User(models.Model):
+    friends = models.ManyToManyField('self', on_delete=models.CASCADE)
+reveal_type(User().friends)  # E: Revealed type is 'django.db.models.manager.RelatedManager[main.User*]'
+[out]