RFR: 8359870: JVM crashes in AccessInternal::PostRuntimeDispatch [v8]

[Kevin Walls]

> ThreadDumper/ThreadSnapshot need to handle a failure to resolve the native VM JavaThread from a java.lang.Thread.  This is hard to reproduce but a thread that has since terminated can provoke a crash.  Recognise this and return a null ThreadSnapshot.

Kevin Walls has updated the pull request incrementally with three additional commits since the last revision:

 - Update src/hotspot/share/services/threadService.cpp
   
   Co-authored-by: David Holmes <62092539+dholmes-ora at users.noreply.github.com>
 - Update src/hotspot/share/services/threadService.cpp
   
   Co-authored-by: David Holmes <62092539+dholmes-ora at users.noreply.github.com>
 - Update src/hotspot/share/services/threadService.cpp
   
   Co-authored-by: David Holmes <62092539+dholmes-ora at users.noreply.github.com>

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/25958/files
  - new: https://git.openjdk.org/jdk/pull/25958/files/e2043438..d56e9d16

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=25958&range=07
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=25958&range=06-07

  Stats: 3 lines in 1 file changed: 1 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/25958.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25958/head:pull/25958

PR: https://git.openjdk.org/jdk/pull/25958