Migrating dmd to D?

[timotheecour]

> Use dtoh to initiate and conduct an incremental port of the 
> compiler.

How about going the other way around?

Using swig to make existing dmd C++ code available to D, so we 
can advance with a mix of D and C++ code until all of C++ code is 
converted.
I was able to successfully convert large code bases from C++ to D 
using swig (eg: opencv, sfml, etc). It's the most hands-off way, 
with very minimal interface file that can recursively make things 
accessible with fine grained control (for opencv the interface 
file was < 200 loc).