Lukas Schwerdt

Add [Pattern-defeating Quicksort](https://arxiv.org/pdf/2106.05123.pdf), an unstable, O(1) space, guaranteed* O(n log n) time variant of quicksort. Both normal, and branchless ([block-](http://arxiv.org/abs/1604.06697)) partitioning schemes are implemented. (*) by falling back to HeapSort...