Fix intval() and floatval() call with a non scalar value

[dravnic]

Here is a code snippet that shows a misleading error when intval() is used with a non-scalar.

<?php

class Foo
{
    private int $x = 0;
    
    function __construct() {
        $this->x += intval(new stdClass());
    }
}

8      Property Foo::$x (int) does not accept (float|int).  

It's reproducible with checkBenevolentUnionTypes: true

I've traced the issue.

intval() with non-scalar argument resolves to ErrorType which is inherited from MixedType.

So ErrorType::toNumber() returns UnionType of int and float. When above math expression is resolved it has int on the left side and float|int on the right side which produces error when checkBenevolentUnionTypes is on.

The root cause is fixed in this PR. It adds non-scalar value handling by making sure that return type for intval/floatval in all cases is int i.e. float.

PHP is throwing a warning on use of non-scalar with intval/floatval and not an error like with strval, so even though non-scalar arguments shouldn't be used we should handle them.

[ondrejmirtes]

Besides this it would also be nice to change the type of intval and floatval parameters to scalar in resources/functionMap.php. Because with non-scalars it produces a warning: https://3v4l.org/Bdim5

[dravnic]

Makes sense. Just added it.

The above code now produces a proper error

Parameter #1 $value of function intval expects bool|float|int|string, stdClass given.

[ondrejmirtes]

Thank you!