Finalize GC memory

[Namespace]

> http://en.wikipedia.org/wiki/Finalizer
>
> It's basically just means calling the finalizer, and D 
> conflates finalizers and
> destructors, so the destructor of any object on the GC heap is 
> that object's
> finalizer. Normally, it's called when the object is collected, 
> but it can get a
> bit messy depending on how the GC works. It's essentially a 
> non-determinstic
> destructor though.
>
> - Jonathan M Davis

It was my fault. What I meant was to release GC memory 
immediately.