Turns out that most of my SNOW-800 patch was included in Viewer 2 (albeit without crediting me).
However, not everything was used and some more cleaning up was possible.

After this patch, and when compiling with optimization, there are no duplicates left
anymore that shouldn't be there in the first place. Apart from the debug stream
iostream guard variable, there are several static variables with the same name (r, r1,
r2, etc) but that indeed actually different symbol objects. Then there are a few
constant POD arrays that are duplicated a hand full of times because they are
accessed with a variable index (so optimizing them away is not possible). I left them
like that (although defining those as extern as well would have been more consistent
and not slower; in fact it would be faster theoretically because those arrays could
share the same cache page then).