glift: Add `-simple-cost-model` option
Rather than assigning specific weights to specific versions of taint tracking logic and summing the weights of all GLIFT cells, sum the following values for each GLIFT cell:
- 0 if the associated hole/$anyconst cell value is non-zero, i.e. reduced-precision taint tracking logic is chosen at this cell
- 1 if the associated hole/$anyconst cell value is zero, i.e. the full-precision taint tracking logic is chosen at this cell
This simplified cost modeling reduces the potential for the QBF-SAT solver to minimize taint tracking logic area but significantly simplifies the QBF-SAT problem.