[jhc] updates to internals documentation

[Henning Thielemann]

On Sat, 20 Mar 2010, John Meacham wrote:

> Unboxed values directly translate to values in the target language, an unboxed
> Int will translate directly into an 'int' as an argument and an unboxed pointer
> will be a raw pointer. Unboxed values have no special interpretation and are
> _not_ followed by the garbage collector. If the target language does not
> support a feature such as multiple return values, it will have to be simulated.
> It would not be wrong to think of Grin code that only deals with unboxed values
> to be isomorphic to C-- or C augmented with multiple return values.

Thank you for the insights!

Everyone is doing LLVM today, so why not JHC? :-)

LLVM supports garbage collection, multiple return values, low-level 
optimizations. It might be more appropriate as compiler back-end than C, 
however certainly less portable. Only a thought of me.