Since the definition and reference lists for each name are accumulated
in reverse order, we take the time at the end of pass1
to
reverse them all so they'll be simpler to print out prettily.
The code for reverse_lists
appears in Section 3.3.
Reverse cross-reference lists ?
{
reverse_lists(file_names);
reverse_lists(macro_names);
reverse_lists(user_names);
}