[lworld] RFR: 8377171: [lworld] Comment warnings for internal valhalla annotations [v2]

[Chen Liang]

> Add some warning comments for value-related annotations in jdk.internal, to discourage their misuse.

Chen Liang has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains three additional commits since the last revision:

 - Merge branch 'lworld' of https://github.com/openjdk/valhalla into doc/value-annos-risk
 - Incorrect statements
 - Warnings for value annotations

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

Changes:
  - all: https://git.openjdk.org/valhalla/pull/2023/files
  - new: https://git.openjdk.org/valhalla/pull/2023/files/c710005d..6a3ed516

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=valhalla&pr=2023&range=01
 - incr: https://webrevs.openjdk.org/?repo=valhalla&pr=2023&range=00-01

  Stats: 15528 lines in 412 files changed: 8486 ins; 3771 del; 3271 mod
  Patch: https://git.openjdk.org/valhalla/pull/2023.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/2023/head:pull/2023

PR: https://git.openjdk.org/valhalla/pull/2023