##### SUMMARY
If a module sets `add_file_common_args=True` when calling `AnsibleModule`, all elements from [FILE_COMMON_ARGUMENTS](https://github.com/ansible/ansible/blob/e9d29b1fe4285d90d7a4506b80260a9e24c3bcea/lib/ansible/module_utils/basic.py#L229-L257) are included in the argument spec. The [files document fragment](https://github.com/ansible/ansible/blob/e9d29b1fe4285d90d7a4506b80260a9e24c3bcea/lib/ansible/plugins/doc_fragments/files.py#L15-L80) only documents a subset of them, though. Missing are:
 - src
 - follow
 - force
 - content
 - backup
 - remote_src
 - regexp
 - delimiter
 - directory_mode

Most module authors using `add_file_common_args=True` are probably not aware that their modules have these options as well.

I don't think these extra options should be added by default if `add_file_common_args=True` is specified.

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
lib/ansible/module_utils/basic.py

##### ANSIBLE VERSION
```
devel
```

param = self.params
        if legal_inputs is None:
            legal_inputs = self._legal_inputs
        for k in list(param.keys()):
            if k not in legal_inputs:
                unsupported_parameters.add(k)
        for k in PASS_VARS:
            
            param_key = '_ansible_%s' % k
            if param_key in param:
                if k in PASS_BOOLS:
                    setattr(self, PASS_VARS[k][0], self.boolean(param[param_key]))
                else:
                    setattr(self, PASS_VARS[k][0], param[param_key])
                
                if param_key in self.params:
                    del self.params[param_key]
            else:
                
                if not hasattr(self, PASS_VARS[k][0]):
                    setattr(self, PASS_VARS[k][0], PASS_VARS[k][1])
        if unsupported_parameters:
            msg = "Unsupported parameters for (%s) module: %s" % (self._name, ', '.join(sorted(list(unsupported_parameters))))
            if self._options_context:
                msg += " found in %s." % " -> ".join(self._options_context)
            msg += " Supported parameters include: %s" % (', '.join(sorted(spec.keys())))
            self.fail_json(msg=msg)
        if self.check_mode and not self.supports_check_mode:
            self.exit_json(skipped=True, msg="remote module (%s) does not support check mode" % self._name)
    def _count_terms(self, check, param=None):