Function chained call

This will allow such syntax:
```php
<?php
(function(){})(); // call an closure
?>
```

```php
<?php
(func())(); // function chained calls
?>
```

```php
<?php
class D {
   public function __invoke() {}
}

(new D)(); // call invoke
?>
```

this patch is refactored, in order to  based on the @nikic 's instance call one(#291).  maybe we can merge them together..

btw: there are some invalid reads report while run with valgrind,, but it seems introduces by nikic's patch,

I will keep looking them.