Z3: improve handling of Z3Exception

Author: kfriedberger

src/org/sosy_lab/java_smt/solvers/z3/Z3OptimizationProver.java

@@ -197,11 +197,11 @@ private Optional<Rational> round(int handle, Rational epsilon, RoundingFunction
   }
 
   @Override
-  protected long getZ3Model() throws InterruptedException {
+  protected long getZ3Model() throws InterruptedException, SolverException {
     try {
       return Native.optimizeGetModel(z3context, z3optSolver);
     } catch (Z3Exception e) {
-      throw new InterruptedException("Z3 model generation interrupted.");
+      throw creator.handleZ3Exception(e);
     }
   }