RFR 8165634: Support multiple --add-module options on the command line

[harold seigel]

Hi,

Please review this fix for JDK-8165634.  The fix changes the 
--add-modules option from being a 'last one wins' option to a cumulative 
one.  With this change, if multiple --add-modules options are specified, 
the VM accumulates all the options' values, instead of ignoring all but 
the last option's value.  The --add-modules values are reported back to 
the JDK as properties using the Arguments::create_numbered_property() 
function.

JBS Bug: https://bugs.openjdk.java.net/browse/JDK-8165634

Open webrevs:

    http://cr.openjdk.java.net/~hseigel/bug_8165634.hs/

    http://cr.openjdk.java.net/~hseigel/bug_8165634.jdk/

The fix was tested with the JCK Lang and VM tests, the hotpot, and 
java/lang, java/util and other JTreg tests, the RBT tier2 tests, and the 
NSK non-colocated quick tests.

The JDK changes were done by Mandy Chung (mchung).

Thanks, Harold