Fix native generator glitch: when it does not trigger flush on save, the property is not yet set to the actual inserted value db side.

Author: fredericDelaporte

src/NHibernate.Test/NHSpecificTest/NH3898/Fixture.cs

@@ -35,14 +35,14 @@ public void GeneratedInsertUpdateTrue()
 					PromotionCount = 9999999
 				};
 				id = session.Save(employee);
-				Assert.That(employee.PromotionCount, Is.EqualTo(0));
 				tx.Commit();
 			}
 
 			using (var session = OpenSession())
 			using (var tx = session.BeginTransaction())
 			{
 				var employee = session.Get<Employee>(id);
+				Assert.That(employee.PromotionCount, Is.EqualTo(0));
 				employee.Name = "Employee 1 changed";
 				employee.PromotionCount++;
 				Assert.That(employee.PromotionCount, Is.EqualTo(1));