Description:
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PHP 7.4 beta 2 returns a different fstat mode value for file pointers than PHP 7.3. This is causing functionality in Slim-Psr7 to break.

Test script:
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<?php

$handle = popen('echo 12', 'r');
$stats = fstat($handle);
var_dump($stats['mode']); // PHP 7.3 prints 4096, PHP 7.4 beta 2 prints 33206

$isPipe = ($stats['mode'] & 0010000) !== 0;
var_dump($isPipe); // PHP 7.3 prints true, PHP 7.4 beta 2 prints false