Segmentation fault in mhash()

### Description

The following code:

```php
<?php
mhash(133, 1086849124, 133);
```

Resulted in this output:
```
/php-src/Zend/zend_operators.c:3064:18: runtime error: member access within null pointer of type 'zend_string' (aka 'struct _zend_string')
```


### PHP Version

nightly

### Operating System

_No response_