No warnings for if-else with instanceof chains

[quasilyte]

Code Example

<?php

class Fooo1 { public $a; }
class Fooo2 { public $b; }

global $globf;

if ($globf instanceof Fooo1) {
    echo $globf->a;
} elseif ($globf instanceof Fooo2) {
    echo $globf->a; // <-- no warnings (bad)
    echo $globf->b;
} else {
    echo $globf->a; // <-- no warnings (bad)
}

Actual Behavior

No warnings.

Expected Behavior

Warning for undefined property a.

The problem is, noverify assigns \Fooo1|\Fooo2 type for $globf inside a second if body, so we can access both Fooo1 and Fooo2 members there.