Fix handling of undeclared static properties in PHP >= 8.2

[cedric-anne]

Fixes phpstan/phpstan#8808.

In PHP 8.2, dynamic properties were deprecated, but, as far as I understand, this change was impacting only non-static properties and was , see https://wiki.php.net/rfc/deprecate_dynamic_properties and https://github.com/nikic/php-src/blob/536d440803477b3bc4950effd357bc5572e37065/Zend/tests/dynamic_prop_deprecation.phpt#L8-L18

Also, isset/empty operations are not triggering any deprecation/warning/exception. The existing exception in the MutatingScope::setAllowedUndefinedExpression() code is therefore not correct

For instance, the following code does not trigger any deprectation/error when executed on PHP 8.2:

class Test {}

isset(Test::$undefprop);
empty(Test::$undefprop);

$test = new Test();
isset($test->undefprop);
empty($test->undefprop);

[ondrejmirtes]

this change was impacting only non-static properties

"Dynamic static properties" were never a thing: https://3v4l.org/3150T

Also, isset/empty operations are not triggering any deprecation/warning/exception.

PHPStan reports a lot of things as problems that are not triggering any kind of error from PHP. For example: https://phpstan.org/r/f8f6f009-a26e-4ea3-b51c-c87e05f6d7f8

It'd be more useful if you opened a bug report or a discussion with the problem you are facing.

[cedric-anne]

this change was impacting only non-static properties

"Dynamic static properties" were never a thing: https://3v4l.org/3150T

I agree that "dynamic properties" is not related to these error, and this is why I do not understand why the behaviour was changed for PHP >= 8.2 in the commit a6857ee, and especially by the following check that seems to indicate that "dynamic properties" are involved here:
https://github.com/phpstan/phpstan-src/blame/d9bdbc2dfe481c16d940e8c045f246991b1e7727/src/Analyser/MutatingScope.php#L3594-L3596

[ondrejmirtes]

Doing #3476 in PHPStan 2.0 as promised.