RFR: 8290059: Do not use std::thread in panama tests

[Jorn Vernee]

On Fri, 22 Jul 2022 15:09:13 GMT, Christoph Langer <clanger at openjdk.org> wrote:

>> This patch removes the use of std::thread from the `java.lang.foreign` tests, and switches to the OS specific thread APIs, in order to change things such as the stack size on some platforms where this is required in the future (see the JBS issue).
>> 
>> This is done by adding a small header-only library that exposes a function to run code in freshly spawned threads (`run_async`).
>> 
>> Testing: Running the affected tests on platforms that implement the linker.
>
> @JornVernee thanks for doing this so quickly. I suggest undoing https://github.com/openjdk/jdk/commit/d7f0de272c85ee8d0890c9d61e10065b618b69d7 in this change, too. If you update this PR I can run it through our Alpine test pipeline.

@RealCLanger Note that I'm not setting the stack size of the thread in this patch. I'm just using the defaults. From the discussion on the bug, I don't think this sufficient to make the tests pass on Apline/MuslC.

I avoided getting into that since I don't have ready access to an Alpine/MuslC testing environment atm. So, I've left setting the stack size on MuslC, and re-enabling the tests for someone that does. Hopefully this patch is enough to get that going easily.

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

PR: https://git.openjdk.org/jdk/pull/9599