Thoughts on bug 15884

[Paul Eggert]

Thanks, Leonhard, for taking this on.  Carlos's suggestions are good 
ones.  One other idea is to see how GNU sort's performance is affected, 
as strcoll has long been a bottleneck in its performance. The fun part 
is that GNU sort is multithreaded, and perhaps that'll give you some 
ideas for your microbenchmark.

Quick war story: I once tried to optimize GNU sort by using strxfrm 
instead of strcoll.  It made performance waaayy worse.  Oops.  To this 
day I don't know what strxfrm is good for in practice.