LanguageServers/cpp: Use parser-based autocomplete engine by default

Userland/DevTools/HackStudio/HackStudioWidget.cpp

@@ -979,6 +979,7 @@ NonnullRefPtr<GUI::Action> HackStudioWidget::create_set_autocomplete_mode_action
     auto action = GUI::Action::create_checkable("AutoComplete C++ with Parser", [this](auto& action) {
         get_language_client<LanguageClients::Cpp::ServerConnection>(project().root_path())->set_autocomplete_mode(action.is_checked() ? "Parser" : "Lexer");
     });
+    action->set_checked(true);
     return action;
 }
 

Userland/DevTools/HackStudio/LanguageServers/Cpp/ClientConnection.cpp

@@ -40,7 +40,7 @@ ClientConnection::ClientConnection(NonnullRefPtr<Core::LocalSocket> socket, int
     : IPC::ClientConnection<LanguageClientEndpoint, LanguageServerEndpoint>(*this, move(socket), client_id)
 {
     s_connections.set(client_id, *this);
-    m_autocomplete_engine = make<LexerAutoComplete>(m_filedb);
+    m_autocomplete_engine = make<ParserAutoComplete>(m_filedb);
 }
 
 ClientConnection::~ClientConnection()