[php-src] Issue #20660: integer overflow in gd.c

Issue: https://github.com/php/php-src/issues/20660
Author: chongwick

### Description

The following code:

```php
<?php
$v_10678 = 8;
$v_10679 = 8;
$v_10680 = imagecreatetruecolor($v_10678,$v_10679,);
$v_10681 = 255;
$v_10682 = 0;
$v_10691 = 64;
$v_10692 = 64;
$v_10693 = imagecreatetruecolor($v_10691,$v_10692,);
$v_10709 = 31;
$v_10406 = '1234567890';
$v_10711 = 50;
$v_10704 = 0;
$v_10705 = 0;
$v_10706 = 0;
$v_10707 = imagecolorallocate($v_10693,$v_10704,$v_10705,$v_10706,);
$v_10712 = imageellipse($v_10693,$v_10681,$v_10709,$v_10406,$v_10711,$v_10707,);
```

Resulted in this output:
```
/home/w023dtc/nightly_php/php-src/ext/gd/libgd/gd.c:1802:7: runtime error: signed integer overflow: 9144947250114312600 + 762078937509526050 cannot be represented in type 'long'
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior /home/w023dtc/nightly_php/php-src/ext/gd/libgd/gd.c:1802:7
```




### PHP Version

```plain
nightly
```

### Operating System

_No response_