preliminary RFR: 8049365 - Update JDI and JDWP for modules

[serguei.spitsyn at oracle.com]

Please, review this initial fix for the Jigsaw Bill milestone task:
https://bugs.openjdk.java.net/browse/JDK-8049365


Jdk webrev:
http://cr.openjdk.java.net/~sspitsyn/webrevs/2015/jdk/8049365-Jigsaw-jdk.0/

Hotspot webrev:
http://cr.openjdk.java.net/~sspitsyn/webrevs/2015/hotspot/8049365-Jigsaw-hs.0/


Summary:

   It is expected that the JDI and JDWP update for modules will have 
several iterations.
   This is the initial one, and it introduces a very minimal functionality.
   The main purpose of this preliminary review is to make sure the JDI 
and JDWP update
   for modules goes in a right direction and has nothing obviously wrong.

   It does not include yet the API's for introspection of the 
ModuleDescriptor, Configuration and Layer.
   There are no convincing use cases for it yet.
   It is still TBD to contact and get more feedback from the NetBeans 
and Eclipse debuggers teams.
   We also could give them our custom build to try.

This fix temporarily adds a VM support for the JDI allModules() as a JNI 
function GetAllModules().
   Any feedback on the Hotspot webrev as to how to implement it better 
is welcome.
   The plan is (as suggested by Alan) to re-implement it on the JVMTI level.

   It is a part of another Jigsaw Bill milestone task:
       https://bugs.openjdk.java.net/browse/JDK-8049364
Update JVM TI for modules

Thanks,
Serguei