char CData can't be directly assigned a number

Description

The following code:

<?php

$v = FFI::new("char[2]");
$v[0] = 65;
var_dump($v);

Resulted in this output:

Fatal error: Uncaught FFI\Exception: Incompatible types when assigning to type 'char' from PHP 'int' in Command line code:1
Stack trace:
#0 {main}
  thrown in Command line code on line 1

But I expected this output instead:

object(FFI\CData:char[2])#1 (2) {
  [0]=>
  string(1) "A"
  [1]=>
  string(1) ""
}

It's somewhat weird to have to type cast around, i.e. I could just do a FFI::cast to uint8_t * and it works. But for some reason, char is special. Seems like an arbitrary restriction to me, and it really should accept both.

PHP Version

master

Operating System

No response

重现 issue 中的 PHP FFI 示例，并跟踪对 char 类型 CData 值进行赋值的处理过程。找到相关的 FFI 实现和现有的 FFI 测试，然后添加将整数赋给 char 的覆盖测试，并验证是否生成了预期的字符值。