[lworld] Integrated: 8334692: [lworld] add missing compiler warnings

[Vicente Romero]

adding warning for value classes declaring a `finalize` method and warnings related to the new serialization

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Commit messages:
 - white space
 - fixing comment
 - fixing comment
 - minor change
 - 8334692: [lworld] add missing compiler warnings

Changes: https://git.openjdk.org/valhalla/pull/1147/files
  Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=1147&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8334692
  Stats: 376 lines in 9 files changed: 324 ins; 9 del; 43 mod
  Patch: https://git.openjdk.org/valhalla/pull/1147.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1147/head:pull/1147

PR: https://git.openjdk.org/valhalla/pull/1147