[lworld] RFR: 8321039: [lworld] Substitutability code must recognize new annotations

[Mandy Chung]

On Wed, 6 Dec 2023 15:44:58 GMT, Roger Riggs <rriggs at openjdk.org> wrote:

>> An initial implementation for substitutability test and partial method handle and var handle support for null-restricted types. JDK-8317767 will provide the full library support for null-restricted types.    
>> 
>> This patch handles null-restricted field reference declared in a non-flat class.  The default value of that field is lazily set by VM on read access.  `Unsafe::getReference` may return null for null-restricted non-flat field.  
>> 
>> A new `jdk.internal.value.ValueClass` is created to provide JVM entry points for value classes until public APIs are defined.     `jdk.internal.misc.newNullRestrictedArray` method is moved as well.
>
> make/data/hotspot-symbols/symbols-unix line 140:
> 
>> 138: JVM_GetTemporaryDirectory
>> 139: JVM_GetVmArguments
>> 140: JVM_GetZeroInstance
> 
> The naming of ZeroInstance and ImplicitlyConstructableClass could be more closely aligned.
> Perhaps GetImplicitlyConstructedInstance.

That's the term described in the JEP.    I prefer to come back and do the renaming later once the APIs are defined.

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PR Review Comment: https://git.openjdk.org/valhalla/pull/960#discussion_r1417761420