Add a precompiled c++ obj file to dub

[Fra Mecca]

Hi all,
I am writing a backend that is partly Vibe.d and partly clucene 
in c++.
I have some object files written in c++ and compiled with g++ 
that are not considered by dub during the linking phase and 
throws `function undefined error ` every time.

Is there a way to tell dub to let dmd handle that .o files?