Clean Executable

[FoxyBrown via Digitalmars-d-learn]

How can we clean an exe from the junk library functions that are 
not actually used by an app. e.g., a hello world program 
shouldn't be 500+kb. I release there are necessary extras like 
the GC, but hell, in a hello world program is it even necessary? 
Does Writeln even use the GC to display a single string?

Seems like D just does not optimize the binaries size. I know 
it's only 500kb, but still.