Andrei, I cannot catch these steps:
1. Implement the dtoh standalone program that takes a D module
and generates its corresponding C++ header.
2. Use dtoh to initiate and conduct an incremental port of the
compiler. At given points throughout the code D code will
coexist and link with C++ code.
Since D is written on C++, what exactly you gonna convert to "C++
header"??
Anyway, I offer to keep away from C++ code - it's written with
"C++ in mind", while D offers brand new world. So I support
rewritting D on D from scratch.
Initially frontend only + join LLVM backend. And next (if we find
LLVM not so well) we can write our own backend.