message: Skip if not dispatch target found on an interface impl
  Summary: The targeted interface hierarchy could have abstract classes where the dispatch target is missing.
diff: @@ -388,7 +388,14 @@ MethodOrderedSet find_dispatch_targets(const TypeSystem& type_system,
  if (type_system.is_subtype(virt_scope->type, impl)) {
  auto target =
  find_matching_virtual_method(type_system, impl, virt_scope);
  - always_assert(target != nullptr);
  + TRACE(RM_INTF, 5, "Found target %s on impl %s", SHOW(target),
  + SHOW(impl));
  + // Skip the current impl if no target is found from it. We currently do
  + // not handle this case. Will fall through to the match completeness
  + // check, and bail out subsequently.
  + if (target == nullptr) {
  + continue;
  + }
  targets.insert(target);
  matched.push_back(impl);
  }
  