RFR (S) 8210512: vmTestbase/nsk/jdi/ObjectReference/referringObjects/referringObjects002/referringObjects002.java fails with unexpected size of ClassLoaderReference.referringObjects

[David Holmes]

Bug: https://bugs.openjdk.java.net/browse/JDK-8210512
Webrev: http://cr.openjdk.java.net/~dholmes/8210512/webrev/

After the fix for JDK-8209361 where we modified JVM-TI to treat an 
unresolved CP klass entry to a loaded klass as a resolved CP entry, the 
listed test starting failing due to finding an extra reference to the 
test class. As outlined in the bug report this extra reference:

17: instance of java.lang.Class(reflected 
class=nsk.share.jdi.TestClass1, id=792)

actually comes from the class itself. Every classfile has a 
self-referential entry in the constant pool (this_klass in JVMS 4.1) and 
that is what we were encountering here.

I would argue that such an unresolved reference from a class to itself 
should never be treated as a "real" reference from a JVM TI perspective, 
and so we ship skip it - which is what the fix does:

- if (klass == NULL) {
+ if (klass == NULL || klass == ik) {
                continue;

Testing: the test concerned
          joatc testing of test that failed in 8209361 (TBD)
          mach5 tiers 1-3 (TBD)
          jvmti (TBD)

As noted testing is still TBD other then actual test but there are 
technical delays with that so I'll get the RFR out anyway.

Thanks,
David