CI lazy methods: scan global initialisers for global references

CI lazy methods now notices cases like global g1 having initialiser &g2, in which case
having a reference to global g1 implies a reference to global g2.

Currently this only happens in the string solver in Java, where a literal's initialiser
references a constant array global.

Author: smowton

src/java_bytecode/ci_lazy_methods.cpp

@@ -479,6 +479,8 @@ void ci_lazy_methodst::gather_needed_globals(
        findit->second.is_static_lifetime)
     {
       needed.add(findit->second);
+      // Gather any globals referenced in the initialiser:
+      gather_needed_globals(findit->second.value, symbol_table, needed);
     }
   }
   else