RFR: 8355003: Implement Ahead-of-Time Method Profiling

[Igor Veresov]

On Sat, 26 Apr 2025 22:32:00 GMT, Vladimir Kozlov <kvn at openjdk.org> wrote:

>> Improve warm-up time by making profile data from a previous run of an application instantly available, when the HotSpot Java Virtual Machine starts. Specifically, enhance the [AOT cache](https://openjdk.org/jeps/483) to store method execution profiles from training runs, reducing profiling delays in subsequent production runs.
>> 
>> More details in the JEP: https://bugs.openjdk.org/browse/JDK-8325147
>
> src/hotspot/share/ci/ciInstanceKlass.hpp line 47:
> 
>> 45:   friend class ciField;
>> 46:   friend class ciReplay;
>> 47:   friend class CompileTrainingData;
> 
> Not referenced here

It allows `CompileTrainingData` to peek into the `ciInstanceKlass` internals. We need the klass ptr specially.

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PR Review Comment: https://git.openjdk.org/jdk/pull/24886#discussion_r2061864230