To be fair, that is because it is a carefully tuned combination of 3 sort routines (quicksort, heapsort, insertion sort), and also optimisations to avoid unnecessary checks for pointers reaching the end of arrays where they can be avoided.

I would be impressed if a sort which used the same 3 combined techniques could be faster.

(Of course, there might be better sorts, such as TimSort, but that's a change of algorithm, not language).