variable.c:557
static void
remove_trace(var)
    struct global_variable *var;
{
    struct trace_var *trace = var->trace;
    struct trace_var t;
    struct trace_var *next;

    t.next = trace;
    trace = &t;
    while (trace->next) {
	next = trace->next;
	if (next->removed) {
	    trace->next = next->next;
	    free(next);
	}
	else {
	    trace = next;
	}
    }
    var->trace = t.next;
}
