-op creates spurious directories

[Jarrett Billingsley]

This is just funny.  If you use -op on the following file:

----[/dmd/proj/test.d]------
import std.c.windows.windows;

void main()
{

}
----------

DMD will generate the directories /dmd/proj/std/c/windows.  It just makes 
them, and they're empty.

I don't think this even warrants a Bugzilla; it's probably just some debug 
code that got left in in 0.168.