8210087: Classes in jdk.unsupported not accessible from jconsole plugin

Reviewed-by: erikj

make/launcher/Launcher-jdk.jconsole.gmk

@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2011, 2015, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2011, 2018, Oracle and/or its affiliates. All rights reserved.
 # DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 #
 # This code is free software; you can redistribute it and/or modify it
@@ -28,6 +28,7 @@ include LauncherCommon.gmk
 $(eval $(call SetupBuildLauncher, jconsole, \
     MAIN_CLASS := sun.tools.jconsole.JConsole, \
     JAVA_ARGS := --add-opens java.base/java.io=jdk.jconsole \
+                 --add-modules ALL-DEFAULT \
 		 -Djconsole.showOutputViewer, \
     CFLAGS_windows := -DJAVAW, \
     LIBS_windows := user32.lib, \