RFR: 8372988: Test runtime/Nestmates/membership/TestNestHostErrorWithMultiThread.java failed: Unexpected interrupt

[David Holmes]

In the fix for JDK-8365526 we changed the `set_nest_host_error` code so that we would overwrite the message in the resolution error table, and free the previous copy of the message (the messages will always be the same). This was the wrong thing to do as the message could be in-use at the time it was freed, leading to either a missing message, or an assertion failure when we checked the messages for UTF8 validity.

The fix is to simply only ever set the message once (freeing it only when the entry is removed from the table).

Testing:
 - TestNestHostErrorWithMultiThread.java with an augmented VM that inserts a delay that helped trigger the bug
 - tiers 1-3 sanity

Thanks

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Commit messages:
 - 8372988: Test runtime/Nestmates/membership/TestNestHostErrorWithMultiThread.java failed: Unexpected interrupt

Changes: https://git.openjdk.org/jdk/pull/28817/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=28817&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8372988
  Stats: 12 lines in 2 files changed: 5 ins; 3 del; 4 mod
  Patch: https://git.openjdk.org/jdk/pull/28817.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/28817/head:pull/28817

PR: https://git.openjdk.org/jdk/pull/28817