RFR: Add alternate desugaring strategy for null-restricted arrays [v3]

[Vicente Romero]

On Fri, 9 Jan 2026 16:39:35 GMT, Maurizio Cimadamore <mcimadamore at openjdk.org> wrote:

>> Creation of null-restricted arrays are desugared as calls into methods of the `ArrayCreation` class, as we need to set the "strict" marker on the created array.
>> Currently the JVM doesn't support creation of null-restricted array for non-value types, so in this PR I cleaned up the `ArrayCreation` API to reflect more what javac needs. Also, according to our long term plans, `ArrayCreation` is really implemented on top of a new primitive in `Array`, which will be refined later to support creation of arrays with desired flags.
>> 
>> The translation strategy in javac is simple -- given an array initializer `{ .. }`, we just assign the initializer to a temp variable, then wrap the initializer using a call to `ArrayCreation::copied` to obtain the new array. Then we wrap everything in a let expression, so that things compose nicely.
>> 
>> While writing the test I realized that our combo framework failed to report compilation and execution failures. As I fixed that issue, I realized that a test I've added (`NullRestrictionReflectiveTest`) was not working correctly, as it had compilaton issues with some of the combinations and even a latent issue in signature parsing which I have now fixed.
>
> Maurizio Cimadamore has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Address review comments

looks good

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Marked as reviewed by vromero (Committer).

PR Review: https://git.openjdk.org/valhalla/pull/1877#pullrequestreview-3644840248