Pick the middle element as the pivot so that our quicksort doesn't have worst case performance for arrays that are already sorted.
Pick the middle element as the pivot so that our quicksort doesn't have worst case performance for arrays that are already sorted.

devtools-html/perf.html,mstange/cleopatra,squarewave/bhr.html,devtools-html/perf.html,squarewave/bhr.html,mstange/cleopatra