remove_funcstack_from_list(funcstack_T *funcstack)
{
    if (funcstack->fs_prev == NULL)
	first_funcstack = funcstack->fs_next;
    else
	funcstack->fs_prev->fs_next = funcstack->fs_next;
    if (funcstack->fs_next != NULL)
	funcstack->fs_next->fs_prev = funcstack->fs_prev;
}
remove_funcstack_from_list(funcstack_T *funcstack)
{
    if (funcstack->fs_prev == NULL)
	first_funcstack = funcstack->fs_next;
    else
	funcstack->fs_prev->fs_next = funcstack->fs_next;
    if (funcstack->fs_next != NULL)
	funcstack->fs_next->fs_prev = funcstack->fs_prev;
}