RFR: 8372380: Make hs_err reporting more robust for unattached threads

[David Holmes]

There were a number of places where the code called by hs_err reporting assumed/required an attached current thread. These would then cause secondary failures during hs_err reporting. Using a simple example of an unattached thread causing a SEGV I went through and eliminated all the problems I encountered. In some cases the thread dependency was obvious and easy to address directly, but in others we just skip that section at the top-level.

Testing:
 - manual inspection of hs_err file, for different GCs
 - tiers 1-3 sanity

Thanks

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Commit messages:
 - Merge branch 'master' into 8369112-crash-unattached
 - 8372380: Make hs_err reporting more robust for unattached threads

Changes: https://git.openjdk.org/jdk/pull/28470/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=28470&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8372380
  Stats: 10 lines in 4 files changed: 5 ins; 0 del; 5 mod
  Patch: https://git.openjdk.org/jdk/pull/28470.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/28470/head:pull/28470

PR: https://git.openjdk.org/jdk/pull/28470