RFR: 8359820: Improve handshake/safepoint timeout diagnostic messages [v8]

[duke]

On Mon, 4 Aug 2025 08:37:23 GMT, Anton Artemov <duke at openjdk.org> wrote:

>> Hi, please consider the following changes:
>> 
>> The problem in the issue description is not a problem by itself, the behavior is not unexpected, but it is somewhat difficult to find out what caused SIGILL to be fired.
>> 
>> We propagate this information from `handshake::handle_timeout()` to `VMError::report()` with a help of a global variable.  The same mechanism is used to address a similar issue in the safepoint timeout handler. 
>> 
>> Tested in tiers 1-3.
>
> Anton Artemov 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 17 additional commits since the last revision:
> 
>  - 8359820: Addressed reviewer's comments
>  - Merge remote-tracking branch 'origin/master' into JDK-8359820-SIGILL-with-low-handshake-timeout-on-intel-sde
>  - 8359820: Addressed reviewer's comments
>  - 8359820: Addressed reviewer's comments
>  - Merge remote-tracking branch 'origin/master' into JDK-8359820-SIGILL-with-low-handshake-timeout-on-intel-sde
>  - 8359820: Fixed spaces
>  - 8359820: Addressed reviewer's comments
>  - 8359820: Addressed reviewer's comments
>  - 8359820: Addressed reviewer's comments
>  - Merge remote-tracking branch 'origin/master' into JDK-8359820-SIGILL-with-low-handshake-timeout-on-intel-sde
>  - ... and 7 more: https://git.openjdk.org/jdk/compare/b65e89c4...d85769af

@toxaart 
Your change (at version d85769af641ce4b9aee02eff30af2a547b468492) is now ready to be sponsored by a Committer.

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PR Comment: https://git.openjdk.org/jdk/pull/26309#issuecomment-3153853570