minor #57795 Use CPP where possible (alexandre-daubois)

This PR was merged into the 7.2 branch.

Discussion
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Use CPP where possible

| Q             | A
| ------------- | ---
| Branch?       | 7.2
| Bug fix?      | no
| New feature?  | no
| Deprecations? | no
| Issues        | -
| License       | MIT

Some places cannot be changed as they rely on "PHP magic" things

Commits
-------

877f6b2951 Use CPP where possible

Iterator/FileTypeFilterIterator.php

@@ -23,16 +23,14 @@ class FileTypeFilterIterator extends \FilterIterator
     public const ONLY_FILES = 1;
     public const ONLY_DIRECTORIES = 2;
 
-    private int $mode;
-
     /**
      * @param \Iterator<string, \SplFileInfo> $iterator The Iterator to filter
      * @param int                             $mode     The mode (self::ONLY_FILES or self::ONLY_DIRECTORIES)
      */
-    public function __construct(\Iterator $iterator, int $mode)
-    {
-        $this->mode = $mode;
-
+    public function __construct(
+        \Iterator $iterator,
+        private int $mode,
+    ) {
         parent::__construct($iterator);
     }