`implode()` order - false positive for PHP 7.4 compatibility 

This is OK:
```php
implode( ' ', [ 'foo', 'bar' ] );
```
however this throws an error:
```php
implode(
  ' ',
  [ 'foo', 'bar' ]
);
```
(PR for that implementation is on https://github.com/PHPCompatibility/PHPCompatibility/pull/846)