Major new feature 🚀

Dependent variables

PHPStan can now understand relationships between different variables. Cases like these are now understood correctly:

if ($debug) {
    $foo = 'bar';
}

if ($debug) {
    // previously: Variable $foo might not be defined.
    // now: no error
    echo $foo;
}

Additionally, this feature fixes all these issues: #801, #806, #1209, #1306, #1722, #1865, #2980, #3371, #3986

Bugfixes 🐛

• Implement property name as an expression in TypesAssignedToPropertiesRule (https://github.com/phpstan/phpstan-src/commit/7458d1e09c00a70ce00453db07f4e2412db599f3)
  
• Updated nikic/php-parser (https://github.com/phpstan/phpstan-src/commit/19bf582aa3c0e0809446a17399d17d17ab40297c), #4194
  

Function signature fixes 🤖

• Changing return type of Collator::compare to int|false (#410), thanks @vasekbrychta!
  
• Update PHP 8 stubs (https://github.com/phpstan/phpstan-src/commit/44305499fe9b4aca8943c8e15382581372f6bd45), #4268