[lworld] RFR: 8373202: [lworld] ObjectReference.equals should follow == semantics for value objects [v2]

[Alex Menkov]

> Updated implementation of ObjectReference.equals and ObjectReference.hashCode to comply the spec for value objects.
> Added the test for value object ctor debugging, the test verifies the behaviour is expected.
> There is an issue with instance filter, it till be fixed separately (it's not yet clear how it would be better to fix it)
> 
> testing: tier1..4, hs-tier5-svc

Alex Menkov has updated the pull request incrementally with one additional commit since the last revision:

  ClassTypeImpl.isValueClass, VirtualMachineImpl.canUseIsSameObject

-------------

Changes:
  - all: https://git.openjdk.org/valhalla/pull/1834/files
  - new: https://git.openjdk.org/valhalla/pull/1834/files/f82f5be4..e74a4cff

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=valhalla&pr=1834&range=01
 - incr: https://webrevs.openjdk.org/?repo=valhalla&pr=1834&range=00-01

  Stats: 37 lines in 4 files changed: 21 ins; 11 del; 5 mod
  Patch: https://git.openjdk.org/valhalla/pull/1834.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1834/head:pull/1834

PR: https://git.openjdk.org/valhalla/pull/1834