Use the task loop to calculate multiple delegated hosts

Due to the way we're now calculating delegate_to, if that value is based
on a loop variable ('item') we need to calculate all of the possible
delegated_to variables for that loop.

Fixes #12499

test/units/playbook/test_play_context.py

@@ -99,8 +99,10 @@ class TestPlayContext(unittest.TestCase):
             ansible_ssh_port = 4321,
         )
 
+        mock_templar = MagicMock()
+
         play_context = PlayContext(play=mock_play, options=options)
-        play_context = play_context.set_task_and_variable_override(task=mock_task, variables=all_vars)
+        play_context = play_context.set_task_and_variable_override(task=mock_task, variables=all_vars, templar=mock_templar)
         self.assertEqual(play_context.connection, 'mock_inventory')
         self.assertEqual(play_context.remote_user, 'mocktask')
         self.assertEqual(play_context.port, 4321)

test/units/vars/test_variable_manager.py

@@ -171,6 +171,7 @@ class TestVariableManager(unittest.TestCase):
 
         mock_task = MagicMock()
         mock_task._role = None
+        mock_task.loop = None
         mock_task.get_vars.return_value = dict(foo="bar")
 
         v = VariableManager()