Fallbacks when missing `declaration-information`

[braised-babbage]

At present, this library is not usable by implementations where declaration-information is unavailable (e.g. ECL). However, some of the macros here might still be reasonable in those contexts. As an example, WITH-EXPECTATIONS could simply evaluate EXPECTATIONS at runtime in that context. This would not be hard to implement, but does come at the cost of a small shift in semantics.