nr2.0: late: Add proper handling for lang item PathInExpressions

gcc/rust/ChangeLog:

	* resolve/rust-late-name-resolver-2.0.cc (Late::visit): Special case lang item paths.

gcc/rust/resolve/rust-late-name-resolver-2.0.cc

@@ -254,8 +254,14 @@ Late::visit (AST::PathInExpression &expr)
   // TODO: How do we have a nice error with `can't capture dynamic environment
   // in a function item` error here?
   // do we emit it in `get<Namespace::Labels>`?
+
   if (expr.is_lang_item ())
-    return;
+    {
+      ctx.map_usage (Usage (expr.get_node_id ()),
+		     Definition (Analysis::Mappings::get ().get_lang_item_node (
+		       expr.get_lang_item ())));
+      return;
+    }
 
   auto resolved
     = ctx.values.resolve_path (expr.get_segments ()).or_else ([&] () {