[Php56][Php70] Handle infinite loop on AddDefaultValueForUndefinedVariableRector+IfToSpaceshipRector

[samsonasik]

Given th following code

class Fixture
{
    public function sortRank($a, $b)
    {
        if ($a == $b) {
            return 0;
        }

        return ($a > $b) ? -1 : 1;
    }
}

It cause crash:

Runtime:       PHP 8.1.13
Configuration: /Users/samsonasik/www/rector-src/phpunit.xml

[1]    14431 segmentation fault  vendor/bin/phpunit tests/Issues/DefaultValueSpaceShip

Ref https://getrector.com/demo/b0b4b1b4-dfd3-4034-a2c7-402b618f56d2
Fixes rectorphp/rector#7788

[samsonasik]

Fixed 🎉 /cc @Freespacer

[samsonasik]

All checks have passed 🎉 @TomasVotruba it is ready for review.

[samsonasik]

@TomasVotruba I am merging it ;)