JEP : Cooperative JFR Sampling (porting work)

[Markus Gronlund]

Greetings,

I am sending this to the porters-dev list as a heads-up for changes involved in JEP Cooperative JFR Sampling [1], which will affect ports if you support the JDK Flight Recorder (JFR) system.

The TemplateInterpreter will need a few changes; please see the files listed in the PR [2].

Technically, the InterpreterMacroAssembler::remove_activation() function will change to pre-emptively move the frame pointer (fp) to the sender frame before issuing a safepoint poll.

No stubs will be provided because the overall changes are extensive and completely change how the JFR system works regarding sampling.

Please feel free to send me patches, and I will incorporate them into the overall PR, or you can wait for a potential integration.

I appreciate your cooperation.
Markus

[1] https://openjdk.org/jeps/8350338
[2] https://github.com/openjdk/jdk/pull/24296