twinapi.appcore: Add RegisterAppStateChangeNotification stub.

dlls/twinapi.appcore/Makefile.in

+EXTRADEFS = -D_CONTRACT_GEN
 MODULE    = twinapi.appcore.dll
+
+C_SRCS = \
+	main.c

dlls/twinapi.appcore/main.c

+/*
+ * Copyright (C) 2023 Mohamad Al-Jaf
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
+ */
+
+#include "appnotify.h"
+#include "wine/debug.h"
+
+WINE_DEFAULT_DEBUG_CHANNEL(twinapi);
+
+/***********************************************************************
+ *           RegisterAppStateChangeNotification (twinapi.appcore.@)
+ */
+ULONG WINAPI RegisterAppStateChangeNotification( PAPPSTATE_CHANGE_ROUTINE routine, void *context, PAPPSTATE_REGISTRATION *reg )
+{
+    FIXME( "routine %p, context %p, reg %p - stub.\n", routine, context, reg );
+    return ERROR_CALL_NOT_IMPLEMENTED;
+}

dlls/twinapi.appcore/twinapi.appcore.spec

@@ -122,6 +122,6 @@
 @ stub PsmUnregisterAppStateChangeNotification
 @ stub PsmWaitForAppResume
 @ stub RegisterAppConstrainedChangeNotification
-@ stub RegisterAppStateChangeNotification
+@ stdcall RegisterAppStateChangeNotification(ptr ptr ptr)
 @ stub UnregisterAppConstrainedChangeNotification
 @ stub UnregisterAppStateChangeNotification