DirectoryIterator significant performance degradation compared to native functions

Having hundreds of installed add-ons on causes progressive performance degradation not related to add-ons code.

I did some debugging and bottleneck profiling and found that the root cause of the problem was DirectoryIterator which is used when traversing addon files in performance-critical places like XF\AddOn\Manager, XF\DevelopmentOutput\DevelopmentOutput and XF\Cli\Runner

Even though an NVMe 1.4 drive is used with high iops, SPL functions has slower execution compared...