All that matters is the behavior, which SQLite has very well defined because it's a bit wonky out of maintaining backwards compatibility. Even the fundamental algorithms will still translate, so all that's needed is to compile it or something logically similar for the system with whatever compiler it allows. Heck, it'd probably be easier than implementing off an abstract spec, especially when you consider most of the optimizations will still translate but do not need to be discovered.

If such a system exists, it won't be able to run the vast majority of stuff out there. Re-implementing SQLite will be the least of its concerns.