Ada -> C or C++ translator

[David Rasmussen <pinkfloydhomer@yahoo.com>]

I know that some Ada features don't have portable counterparts in C or 
C++ (like concurrency), but does some sort of translator exist from Ada 
to C or C++? It could use C or C++ as an Intermediate Representation 
language similar to what the Comeau C/C++ compiler does. This way, one 
could do the development with Ada and have all the advantages of Ada, 
and end up with hopefully more correct code, and then for the release, 
one could translate to C or C++ and use some of the very effecient 
compilers for these languages. I realize that the support of some parts 
of Ada's runtime system (like exceptions) wont be intact, but for 
projects where this isn't important, such a translator could still be 
useful.

Does such a translator exist?

/David