-- Fixed mil dead code elimination. It should now avoid modifying the code    in case NDEBUG is set (= if dirty variables are maintained).
-- Fixed mil dead code elimination. It should now avoid modifying the code
   in case NDEBUG is set (= if dirty variables are maintained).

   The inference of the used variables and the dirty variables now happens
   in one tree traversal. If we do not need to infer the used variables
   a traversal without changes is introduced for the dirty variables.

zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb