Fixed #35044 -- Avoided clearing reverse relations and private fields when accessing deferred fields.

Regression in a7b5ad8b19 for reverse
relations and possibly in 123b1d3fcf for
private fields.

tests/defer/models.py

@@ -19,6 +19,14 @@ class Primary(models.Model):
         return self.name
 
 
+class PrimaryOneToOne(models.Model):
+    name = models.CharField(max_length=50)
+    value = models.CharField(max_length=50)
+    related = models.OneToOneField(
+        Secondary, models.CASCADE, related_name="primary_o2o"
+    )
+
+
 class Child(Primary):
     pass