__CLASS__ no longer has the MAGIC_CLASS flag in PHP 8.3's native AST

[Daimona]

I noticed that, when using PHP 8.3, phan wasn't able to recognize callables using the __CLASS__ constant, like [ __CLASS__, 'methodName' ]. Upon digging a bit, I noticed that the AST generated by php-ast is different, in that the AST_MAGIC_CONST node no longer has the MAGIC_CLASS flag:

$ php8.2 internal/dump_fallback_ast.php --php-ast-native '__CLASS__;'
AST_STMT_LIST [] #1
	0 => AST_MAGIC_CONST [MAGIC_CLASS] #1

$ php8.3 internal/dump_fallback_ast.php --php-ast-native '__CLASS__;'
AST_STMT_LIST [] #1
	0 => AST_MAGIC_CONST [] #1

Therefore, phan can no longer recognize the __CLASS__ constant, which leads to a number of issues such as not resolving callables that use it.

---

Some more information:

$ php8.3 --version
PHP 8.3.3-1+ubuntu22.04.1+deb.sury.org+1 (cli) (built: Feb 15 2024 18:38:52) (NTS)
Copyright (c) The PHP Group
Zend Engine v4.3.3, Copyright (c) Zend Technologies
    with Zend OPcache v8.3.3-1+ubuntu22.04.1+deb.sury.org+1, Copyright (c), by Zend Technologies

$ php8.3 -r "echo phpversion('ast');"
1.1.1

I first spotted this notice in a continuous integration environment a month ago, but I couldn't reproduce it locally with my version of PHP 8.3. While I can't be 100% sure, I likely had 8.3.2 at the time (or 8.3.1 at most), so it might be a regression in PHP 8.3.3.

Finally, note that this still works fine when using the polyfill parser:

 $ php8.3 internal/dump_fallback_ast.php --php-ast '__CLASS__;'
AST_STMT_LIST [] #1
	0 => AST_MAGIC_CONST [MAGIC_CLASS] #1

I don't know if this is a bug in php-ast or phan, but phan is affected nonetheless.