Find a way to handle relative file paths in phpstans checkstyle report in combination with full paths from other reports.

[calbrecht]

Parsing a checkstyle report from phpstan together with reports that have absolute paths for files results in lot of warnings and finally in out of memory error.

Warning: strrpos(): Offset is greater than the length of haystack string 
in /home/user/path/to/PHP_CodeBrowser/src/PHPCodeBrowser/View/ViewAbstract.php on line 228
...
Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 98566152 bytes) 
in /home/user/path/to/PHP_CodeBrowser/src/PHPCodeBrowser/View/ViewAbstract.php on line 230```

The reason is the common ancestor logic where phpcb tries to find a common ancestor between relative and full paths.