Bug report

When a class method contains two unbounded generics which are both used in the condition part of the conditional return, PHPStan thinks that these two would always be the same. In this example:

final class Choice
{
        /**
	 * @template T
         * @template S
         *
         * @param T $value
         * @param S $none
         *
         * @return (T is S ? None : Some<T>)
         */
        public static function from(mixed $value, mixed $none = null): Option
        {
            if ($value === $none) {
                return new None();
            }

            return new Some($value);
	}
}

it is assumed the function will always return None as T would be always the same as S. However, from the dumps it can be shown the correct types are inferred by PHPStan.

Code snippet that reproduces the problem

https://phpstan.org/r/1fbbf61a-a336-4855-9ba8-e873384a5fb1

Expected output

No error for that part.

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