Round #1: 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.1/


Hotspot webrev:
http://cr.openjdk.java.net/~sspitsyn/webrevs/2015/hotspot/8049365-Jigsaw-hs.1/


Summary:
   This round includes most of the changes suggested or discussed by 
Alan in the round #0:
     - The version 1.9 is replaced version
     - The Module interface is replaced with the ModuleReference 
interface that extends the ObjectReference.
     - The argument name "target" in the CanRead is replaced with 
"source" to make it consistent with
        the class java.lang.reflect.Module.
     - The public field TRACE_MODULES has been removed.
     - Some other small changes.
        I hope, all comments are addressed. But, please, let me know if 
anything is missed.


   This round does not include the corresponding update of the SA-JDI.
   I'm suggesting to separate and postpone this part for now to speed up 
the main part.
   Another reason for it is that the SA-JDI update depends on possible 
VM changes.

   This round adds new capability "can_get_modules_info" that is 
appeared on all levels:
      JVMTI, JDWP and JDI.

   It is expected that the JDI and JDWP update for modules will have 
more iterations.
   This is the initial one, and it introduces minimal functionality.

   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 includes JVMTI support for the JDI allModules() as a JVMTI 
function GetAllModules().
   Any feedback on the Hotspot webrev as to how to implement it better 
is welcome.
   We agreed with Lois that some adjustments or tweaks from her will be 
necessary.


   Also, please, refer to a related Jigsaw Bill milestone task:
https://bugs.openjdk.java.net/browse/JDK-8049364
Update JVM TI for modules


Thanks,
Serguei