RFR: 8288497: add support for JavaThread::is_oop_safe() [v3]

[Daniel D. Daugherty]

On Fri, 17 Jun 2022 15:21:01 GMT, Daniel D. Daugherty <dcubed at openjdk.org> wrote:

>> A fix to add support for JavaThread::is_gc_barrier_detached() which allows
>> us to add checks to detect failures like:
>> 
>>     JDK-8288139 JavaThread touches oop after GC barrier is detached
>>     https://bugs.openjdk.org/browse/JDK-8288139
>> 
>> This fix along with the fix for JDK-8288139 has been tested in Mach5 Tier[1-8].
>> There are no related failures in Mach5 Tier[1-7]; Mach5 Tier8 is still running.
>
> Daniel D. Daugherty has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Rename cannot_access_oops_safely to is_oop_safe and invert the function's logic.

The latest version's Mach5 Tier[1-7] looks good. Mach5 Tier8 was just started.

@dholmes-ora - please re-review when you get the chance.

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PR: https://git.openjdk.org/jdk19/pull/20