Add some warning comments for value-related annotations in jdk.internal, to discourage their misuse.
------------- Commit messages: - Warnings for value annotations Changes: https://git.openjdk.org/valhalla/pull/2023/files Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=2023&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8377171 Stats: 36 lines in 2 files changed: 18 ins; 0 del; 18 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
