Choose better sorting and priority queue algorithms

[pczarn]

• Gather statistics about the order of item arrays to better choose algorithms.
• Implement an unstable, O(n log n) time, constant space sorting algorithm that work fast on small and medium-sized arrays -- probably a combination of pattern-defeating quicksort and insertion sort.
• Implement a special case for the priority queue that works fast on small arrays of tiny elements. For example, on up to 32 byte-sized elements.

[pczarn]

The Rust standard library already uses efficient sorting algorithms such as unstable pdqsort. Fortunately, our sort can be unstable.

[pczarn]

Let's use a branchless binary search algorithm.