[php-src] Issue #8469: Phar Class decompressFiles() bad in PHP 7.4 and 8.x branches

Issue: https://github.com/php/php-src/issues/8469 Comment Author: cmb69 Thanks for reporting! I can reproduce the reported behavior (funnily, the given code is basically the same as the [example given for Phar::decompressFiles()](https://www.php.net/manual/en/phar.decompressfiles.php#refsect1-phar.decompressfiles-examples), but apparently that never worked properly). > Since there is no 'isCompressed()' function it should cause an exception. There is PharData::isCompressed(); it is just not documented (like 25 other methods of PharData).