UndefinedPropertyFetch should not be emitted when within a property_exists check

[mr-feek]

https://psalm.dev/r/7b8648a68c

I assume very related to #4182

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/7b8648a68c

<?php

class Foo
{
    public function __construct(array $data)
    {
        foreach ($data as $key => $value) {
            $this->{$key} = $value;
        }
    }
}

$foo = new Foo(['bar' => 'hello']);

if (property_exists($foo, 'bar')) {
    echo $foo->bar;
}

Psalm output (using commit f5bc841):

ERROR: UndefinedPropertyFetch - 16:10 - Instance property Foo::$bar is not defined

INFO: MixedArgument - 16:10 - Argument 1 of echo cannot be mixed, expecting string

INFO: MixedAssignment - 7:35 - Unable to determine the type that $value is being assigned to

[niconoe-]

Same here, but the weird thing is that methods into method_exists checks are ok.

https://psalm.dev/r/2d09a2b002

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/2d09a2b002

<?php

class A
{
    public function test(array $array): mixed
    {
        if (property_exists($this, 'xProperties')) {
            return $this->xProperties;
        }
        
        if (method_exists($this, 'testing')) {
            return $this->testing($array);
        }
        
        return null;
    }
}

Psalm output (using commit 285fa13):

ERROR: UndefinedThisPropertyFetch - 8:20 - Instance property A::$xProperties is not defined

[orklah]

duplicate of #2206