RFR(L) 8136930: Simplify use of module-system options by custom launchers

[Alan Bateman]

On 20/07/2016 22:47, Coleen Phillimore wrote:

>
>
> Why aren't addmods and limitmods allowed be specified more than once 
> on the command line and handled like the other ones?
It's last one wins, typical for most options when repeated. I could 
imagine someone composing a command line with --add-modules coming from 
multiple sources, they logically merge/union, so maybe there is a case 
for that. However --limit-modules is niche and I don't think makes sense 
to attempt to merge.

>
> We should add an option -XX:+UseUnsafe to be a shortcut for this:
>
> --add-exports=java.base/jdk.internal.misc=ALL-UNNAMED
That may be useful for JDK tests but it makes it too easy to get to 
jdk.internal.misc.Unsafe. For usages outside of the JDK then I think 
they should continue to use sun.misc.Unsafe (JEP 260 etc.) and gradually 
reduce that over time as better approaches are available in the platform.

-Alan