[jdk25u] RFR: 8361363: ShenandoahAsserts::print_obj() does not work for forwarded objects and UseCompactObjectHeaders

[Vishal Chand]

Backport of:
* JDK-8361363 - ShenandoahAsserts::print_obj() does not work for forwarded objects and UseCompactObjectHeaders
 * This change fixes Shenandoah’s print_obj() so it correctly prints forwarded objects when compact object headers are enabled, instead of crashing by reading an invalid klass from the forwarding pointer.

Risk is Low as this is a clean backport and the changes are in diagnostic code.

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Commit messages:
 - Backport fe264676337cdef0d7477b0b57ff9d2fe8f9fc0f

Changes: https://git.openjdk.org/jdk25u/pull/384/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk25u&pr=384&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8361363
  Stats: 3 lines in 1 file changed: 2 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk25u/pull/384.diff
  Fetch: git fetch https://git.openjdk.org/jdk25u.git pull/384/head:pull/384

PR: https://git.openjdk.org/jdk25u/pull/384