static vars must allow expressions

Hello!

I would like to suggest that static vars must allow expressions too.
Currently it only supports scalar values, but different to consts, it could
be manipulated by its own function that uses that.

https://www.php.net/manual/en/language.variables.scope.php#language.variables.scope.static

Currently you could uses like:

function test() {
static $x;
$x++;
var_dump($x);
}

test(); // 1
test(); // 2

So my idea is allow an initial value to be defined by a more complex
expression, like:

function test() {
static $configurationHandler = Configuration::getInstance();
$configurationHandler->doSomething();
}

Additionally, I thought that it might be necessary to implement some new
methods for ReflectionFunction / ReflectionMethod, in which it allows to
reset or check the current value.

(new ReflectionFunction('test'))->hasStaticVariable('x'); // true
(new ReflectionFunction('test'))->issetStaticVariable('x'); // true
(new ReflectionFunction('test'))->setStaticVariable('x', 123); // void
(new ReflectionFunction('test'))->getStaticVariable('x'); // 2
(new ReflectionFunction('test'))->unsetStaticVariable('x'); // void

or

(new ReflectionFunction('test'))->getStaticVariable('x'); //
ReflectionProperty (or ReflectionVariable)

One of the questions that can happen is about the context conflict, but it
already occurs:

class Test {
public function test(): void {
static $x = 0;

    $x++;

    var_dump($x);
}

}

(new Test)->test(); // 1
(new Test)->test(); // 2

Note that $x will share the context like a static property, even if it been
called from a non-static context.

Atenciosamente,
David Rodrigues