StrvalToTypeCastRector crash with variadic param

[NicoImparfait]

Bug Report

Subject	Details
Rector version	e.g. v0.17.0 (invoke vendor/bin/rector --version)

Rector crash due to StrvalToTypeCastRector when using strval with variadic param

https://getrector.com/demo/bbbf6bbc-d903-4940-ae03-7b06782ffcde

• on version 0.17.0 I have the following error:

"System error: "PhpParser\Node\Expr\Cast::__construct(): Argument #1 ($expr) must be of type
         PhpParser\Node\Expr, null given, called in
         vendor/rector/rector/rules/CodeQuality/Rector/FuncCall/StrvalToTypeCastRector.php57"

• from getrector (commit 7cde41), I have the following error:

"System error: "Undefined property: PhpParser\Node\VariadicPlaceholder::$value"

Minimal PHP Code Causing Issue

<?php

final class DemoFile
{
    public function run()
    {
      return array_map(strval(...), [1, 2, 3]);
    }
}

Expected Behaviour

<?php

final class DemoFile
{
    public function run()
    {
          return array_map(fn($arg) => (string) $arg, [1, 2, 3]);
    }
}

[samsonasik]

@NicoImparfait Could you try provide a patch for it? You can add:

        if (! $node->isFirstClassCallable()) {
            return null;
        }

before check arg on https://github.com/rectorphp/rector-src/blob/7cde4132f7705a0f941867d66c909abd114e758d/rules/CodeQuality/Rector/FuncCall/StrvalToTypeCastRector.php#L66

Then, add fixture test case on https://github.com/rectorphp/rector-src/tree/main/rules-tests/CodeQuality/Rector/FuncCall/StrvalToTypeCastRector/Fixture for first class callable usage.

You can create separate file with skip_ prefix fixture for it, for example:

https://github.com/rectorphp/rector-src/blob/main/rules-tests/CodeQuality/Rector/FunctionLike/RemoveAlwaysTrueConditionSetInConstructorRector/Fixture/skip_constant_strings_without_value.php.inc