[lworld] RFR: 8326598: [lworld] JVM must support field inheritance for value classes

[Frederic Parain]

Adds field inheritance for value classes.
Layouts of value classes that inherited fields are not always optimal, but fixing them would require a new placement algorithm which is beyond the scope of this CR.
The test is currently limited to the interpreted mode because of issues with CI and C2 tracked by JDK-8331964.

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Commit messages:
 - Cleanup
 - Restrict test to interpreted mode for now
 - Merge remote-tracking branch 'upstream/lworld' into field_inheritance
 - Fix test after merge
 - Merge remote-tracking branch 'upstream/lworld' into field_inheritance
 - Field inheritance test, VM fixes, layout analyzer improvements
 - Merge remote-tracking branch 'upstream/lworld' into field_inheritance
 - Field inheritance first step

Changes: https://git.openjdk.org/valhalla/pull/1103/files
  Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=1103&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8326598
  Stats: 498 lines in 5 files changed: 361 ins; 39 del; 98 mod
  Patch: https://git.openjdk.org/valhalla/pull/1103.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1103/head:pull/1103

PR: https://git.openjdk.org/valhalla/pull/1103