Fixed-Length Array Sorting

[Andrei Alexandrescu via Digitalmars-d]

Also to avoid cache line thrashing, sort parallel swaps by leftmost 
index. E.g. this line:

18,19, 20,21, 2,4, 1,3, 0,5, 6,8, 7,9, 10,12, 11,13,

becomes:

0,5, 1,3, 2,4, 6,8, 7,9, 10,12, 11,13, 18,19, 20,21,


Andrei