fix java_string_literals

Author: Daniel Kroening

src/java_bytecode/java_bytecode_parser.cpp

@@ -552,6 +552,7 @@ void java_bytecode_parsert::rconstant_pool()
       {
         symbol_typet string_type("java::java.lang.String");
         exprt result(ID_java_string_literal, pointer_typet(string_type));
+        result.set(ID_value, pool_entry(it->ref1).s);
         it->expr=result;
       }
       break;