Other build issues on macOS with clang 17.0.0: issue #1

[Marc Culler]

I encountered and fixed several issues.  I will send them in separate messages to try to avoid confusion.

#1. libsemigroups does not build.  Adding the following patch fixes it:

diff --git a/include/libsemigroups/sims1.tpp b/include/libsemigroups/sims1.tpp
index bc8bda37..69884522 100644
--- a/include/libsemigroups/sims1.tpp
+++ b/include/libsemigroups/sims1.tpp
@@ -619,7 +619,7 @@ namespace libsemigroups {
   typename Sims1<T>::iterator_base&
   Sims1<T>::iterator_base::operator=(Sims1<T>::iterator_base&& that) {
     _extra           = std::move(that._extra);
-    _longs           = std::move(that.long_rules());
+    _longs           = std::move(that._longs);
     _max_num_classes = std::move(that._max_num_classes);
     _min_target_node = std::move(that._min_target_node);
     _felsch_graph    = std::move(that._felsch_graph);