##### 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
```

role_name = include_args.pop('name', include_args.pop('role', None))
                        if role_name is not None:
                            role_name = templar.template(role_name)
                        new_task = original_task.copy()
                        new_task._role_name = role_name
                        for from_arg in new_task.FROM_ARGS:
                            if from_arg in include_args:
                                from_key = from_arg.replace('_from', '')
                                new_task._from_files[from_key] = templar.template(include_args.pop(from_arg))
                        inc_file = IncludedFile(role_name, include_args, special_vars, new_task, is_role=True)
                    idx = 0
                    orig_inc_file = inc_file
                    while 1:
                        try:
                            pos = included_files[idx:].index(orig_inc_file)
                            
                            
                            inc_file = included_files[idx + pos]
                        except ValueError:
                            included_files.append(orig_inc_file)
                            inc_file = orig_inc_file
                        try:
                            inc_file.add_host(original_host)
                        except ValueError:
                            
                            idx += pos + 1
                        else:
                            break
        return included_files