Upcoming FFM API integration/finalization

[Jorn Vernee]

Hey folks,

We are coming up on the integration of JEP 454, the Foreign Function & 
Memory API [1]. As outlined in my email in March [2], the finalization 
of this API will mean that a linker implementation is required on all 
platforms. If the platform you are maintaining does not have a linker 
implementation, tests in ./test/jdk/java/lang/foreign will start failing 
after the integration, as they now require the linker API to be present.

Many porters have already integrated full ports of the Linker for their 
platform (thanks!). It is also possible to use a 'fallback' linker 
implementation, which is based on libffi, by configuring/building the 
JDK with --enable-fallback-linker (this will of course also required 
libffi to be available. See email from March).

If you haven't already, I encourage testing the JEP 454 changes ahead of 
the integration. You can find the changes in the main JEP PR [3]. The 
body of the pull request contains instructions on how to pull these 
changes to a local machine using several methods.

Cheers,
Jorn

[1]: https://bugs.openjdk.org/browse/JDK-8310626
[2]: https://mail.openjdk.org/pipermail/porters-dev/2023-March/000753.html
[3]: https://github.com/openjdk/jdk/pull/15103