##### SUMMARY
Setting `extended: yes` in `loop_control` doesn't provide `ansible_loop` inside the loop.

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
loop_control

##### ANSIBLE VERSION
```
ansible 2.9.0.dev0
  config file = None
  configured module search path = ['/home/kustodian/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /home/kustodian/git/github/ansible/lib/ansible
  executable location = /home/kustodian/git/github/ansible/bin/ansible
  python version = 3.7.4 (default, Jul 16 2019, 07:12:58) [GCC 9.1.0]
```
This also doesn't work on 2.8.4

##### CONFIGURATION
```
```

##### OS / ENVIRONMENT
ArchLinux

##### STEPS TO REPRODUCE
Create two files:
```yaml
# play.yml
---
- hosts: localhost
  connection: local
  tasks:
    - include_tasks: inner.yml
      loop:
        - 1
        - 2
        - 3
      loop_control:
        extended: yes
```
```
# inner.yml
- debug:
    var: ansible_loop
```
and run:
```
ansible-playbook play.yml -i localhost,
```

##### EXPECTED RESULTS
Ansible should print the value of `ansible_loop` three times.

##### ACTUAL RESULTS
It actually prints that `ansible_loop` is undefined:
```
$ ansible-playbook play.yml -i localhost,

PLAY [localhost] *******************************************************************************************************************************************************************************************

TASK [Gathering Facts] *************************************************************************************************************************************************************************************
ok: [localhost]

TASK [include_tasks] ***************************************************************************************************************************************************************************************
included: /tmp/inner.yml for localhost
included: /tmp/inner.yml for localhost
included: /tmp/inner.yml for localhost

TASK [debug] ***********************************************************************************************************************************************************************************************
ok: [localhost] => {
    "ansible_loop": "VARIABLE IS NOT DEFINED!"
}

TASK [debug] ***********************************************************************************************************************************************************************************************
ok: [localhost] => {
    "ansible_loop": "VARIABLE IS NOT DEFINED!"
}

TASK [debug] ***********************************************************************************************************************************************************************************************
ok: [localhost] => {
    "ansible_loop": "VARIABLE IS NOT DEFINED!"
}

PLAY RECAP *************************************************************************************************************************************************************************************************
localhost                  : ok=7    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0
```

templar = Templar(loader=loader, variables=task_vars)
                    if original_task.action in ('include', 'include_tasks'):
                        include_file = None
                        if original_task:
                            if original_task.static:
                                continue
                            if original_task._parent:
                                
                                
                                parent_include = original_task._parent
                                cumulative_path = None
                                while parent_include is not None:
                                    if not isinstance(parent_include, TaskInclude):
                                        parent_include = parent_include._parent
                                        continue
                                    if isinstance(parent_include, IncludeRole):
                                        parent_include_dir = parent_include._role_path
                                    else:
                                        try:
                                            parent_include_dir = os.path.dirname(templar.template(parent_include.args.get('_raw_params')))
                                        except AnsibleError as e:
                                            parent_include_dir = ''
                                            display.warning(
                                                'Templating the path of the parent %s failed. The path to the '
                                                'included file may not be found. '
                                                'The error was: %s.' % (original_task.action, to_text(e))
                                            )
                                    if cumulative_path is not None and not os.path.isabs(cumulative_path):
                                        cumulative_path = os.path.join(parent_include_dir, cumulative_path)
                                    else: