message: hopefully fix crash in constraints
  fixes microsoft/vcpkg#17269
diff: @@ -1481,7 +1481,18 @@ namespace vcpkg::Dependencies
  }
  auto& dep_node = emplace_package(dep_spec);
  + if (dep_spec == ref.first)
  + {
  + // this is a feature dependency for oneself
  + for (auto&& f : dep.features)
  + {
  + add_constraint(ref, f, ref.first.name());
  + }
  + }
  + else
  + {
  add_constraint(dep_node, dep, ref.first.name());
  + }
  p.first->second.emplace_back(dep_spec, "core");
  for (auto&& f : dep.features)
  