Interval-tnum reduced product

[alegs-a]

A domain computing the reduced product of the interval and tnum analyses. For a whole lot of words, go read winter_research_reduced_product.pdf

[alegs-a]

This can't be merged yet because the known bits analysis doesn't play nicely. Specifically, getting variables out of known bits' map (unreduced._2(v)) on line 88 of Domains.scala will cause a crash if that variable doesn't exist. This is the reason for the test which currently fails. If the known bits analysis used a LatticeMap then we could .getOrElse() to go to bottom in this case, or there are probably other ways of gracefully handling this that I'm not aware of.

[agle]

My plan with this is to refactor this on top of a single-value domain abstraction to avoid the complexity of computing the reduced product of two different map types. This means waiting for a slightly substantial refactor of the known bits analysis.