RFR: 8366178: Implement JEP 526: Lazy Constants (Second Preview) [v25]

[ExE Boss]

On Wed, 12 Nov 2025 10:07:39 GMT, Per Minborg <pminborg at openjdk.org> wrote:

>> Implement JEP 526: Lazy Constants (Second Preview)
>> 
>> The lazy list/map implementations are broken out from `ImmutableCollections` to a separate class.
>> 
>> The old benchmarks are not moved/renamed to allow comparison with previous releases.
>> 
>> `java.util.Optional` is updated so that its field is annotated with `@Stable`.  This is to allow `Optional` instances to be held in lazy constants and still provide constant folding.
>
> Per Minborg has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 112 commits:
> 
>  - Clarify toString spec
>  - Merge branch 'master' into lazy-constants
>  - Add @AOTSafeClassInitializer
>  - Address comments in PR
>  - Fix merge mistake
>  - Merge master
>  - Rework toString implementations
>  - Update after doc comments
>  - Merge branch 'master' into lazy-constants
>  - Revert the AbstractMap.keySet @Stable annotation
>  - ... and 102 more: https://git.openjdk.org/jdk/compare/76a1109d...1f439bec

src/java.base/share/classes/java/util/LazyCollections.java line 509:

> 507:                 return mutex;
> 508:             }
> 509:             // Protect against racy stores of mutexe candidates

Suggestion:

            // Protect against racy stores of mutex candidates

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

PR Review Comment: https://git.openjdk.org/jdk/pull/27605#discussion_r2518540555