Don't add unsupported items to the list of toplevel items.

PiperOrigin-RevId: 840405417

Author: zrlk

rs_bindings_from_cc/importer.cc

@@ -606,6 +606,20 @@ void Importer::Import(clang::TranslationUnitDecl* translation_unit_decl) {
   llvm::copy(GetOrderedItemIdsOfTemplateInstantiations(),
              std::back_inserter(
                  invocation_.ir_.top_level_item_ids[invocation_.target_]));
+
+  // Remove any unsupported items.
+  for (auto& [label, item_ids] : invocation_.ir_.top_level_item_ids) {
+    item_ids.erase(
+        std::remove_if(
+            item_ids.begin(), item_ids.end(),
+            [&](ItemId item_id) {
+              auto it = import_cache_.find(
+                  reinterpret_cast<clang::Decl*>(item_id.value()));
+              return it != import_cache_.end() && it->second.has_value() &&
+                     std::holds_alternative<UnsupportedItem>(*it->second);
+            }),
+        item_ids.end());
+  }
 }
 
 void Importer::ImportDeclsFromDeclContext(