Draft: Snoop: fixes dep_graph.ml and adds a graph visualization with variables
This MR fixes dep_graph.ml:
- Fixes #4840
- Simplifies types of functions in Solver
- Hide implementations by minimizing dep_graph.mli
It also adds free variables to the dependency graph visualization. For example:
We see here there are ambiguity who provides N_ILsl_bytes_shift and N_ILsl_bytes_const.
Edited by Jun Furuse