[php-src] Issue #22387: AST pretty-printing drops meaningful parentheses around RHS of `instanceof`

Issue: https://github.com/php/php-src/issues/22387
Author: TimWolla

### Description

The following code:

```php
<?php

$foo = new stdClass();
const bar = 'stdClass';

try {
	assert(!$foo instanceof (bar));
} catch (AssertionError $e) {
	echo $e->getMessage(), PHP_EOL;
}
```

Resulted in this output:
```
assert(!$foo instanceof bar)
```

But I expected this output instead:
```
assert(!$foo instanceof (bar))
```


### PHP Version

```plain
PHP 8.6.0-dev (cli) (built: Jun 21 2026 18:51:23) (ZTS DEBUG)
Copyright © The PHP Group and Contributors
Zend Engine v4.6.0-dev, Copyright © Zend by Perforce
    with Zend OPcache v8.6.0-dev, Copyright ©, by Zend by Perforce
```

### Operating System

_No response_