[Bug libstdc++/58437] [4.7/4.8/4.9 Regression] Sorting value in reverse order is much slower compare to gcc44

[chris at bubblescope dot net]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58437

--- Comment #7 from Chris Jefferson <chris at bubblescope dot net> ---
I will look at this next week. Quicksorts are always suboptimal for mostly
sorted (forwards or backwards) data, and it would be nice to fix that.