[Performance] shootout.binarytrees when implemented with gc is 10x slower than C# on .NET 2.0

[Craig Black]

That really sucks.

Eventually, I know that it is Walter's intention to  optimize D's GC.  In
the mean time, when performance is critical, we can do heap allocation in
the traditional manner using malloc and free.  However, IMO, there should be
a more simple way to do this than overloading new and delete.

-Craig