[lworld] RFR: 8262104: [lworld] Runtime should automagically have primitive classes implement PrimitiveObject

[David Simms]

Follows in the footsteps of JDK-8245216: [lworld] The JVM should inject the IdentityObject interface to types which need it
Also includes a similar footprint tweak to JDK-8245646: [lworld] LW3 Reduce impact of IdentityObject on metaspace

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Commit messages:
 - 8262104: [lworld] Runtime should automagically have primitive classes implement PrimitiveObject

Changes: https://git.openjdk.java.net/valhalla/pull/349/files
 Webrev: https://webrevs.openjdk.java.net/?repo=valhalla&pr=349&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8262104
  Stats: 406 lines in 20 files changed: 382 ins; 10 del; 14 mod
  Patch: https://git.openjdk.java.net/valhalla/pull/349.diff
  Fetch: git fetch https://git.openjdk.java.net/valhalla pull/349/head:pull/349

PR: https://git.openjdk.java.net/valhalla/pull/349