Adding BitVectors literals arithmetic simplification
Created by: mario-bucev
Note: targets the scala-3.x
branch.
That addition is needed for some tests in GenC
(with the Dotty frontend) to succeed (more specifically, some arrays require a literal size). The Stainless extraction happens before the constant unfolding in the Dotty pipeline.
The other two minor changes are here to help with negative tests checks (for later on)