[lworld] RFR: 8327636: [lworld] Make primitive wrappers be value class if preview feature is enabled

[Chen Liang]

On Thu, 7 Mar 2024 22:45:41 GMT, Mandy Chung <mchung at openjdk.org> wrote:

> As specified in JEP 401, when preview features are enabled, the following standard library classes are considered to be value classes:
> 
>     java.lang.Byte
>     java.lang.Short
>     java.lang.Integer
>     java.lang.Long
>     java.lang.Float
>     java.lang.Double
>     java.lang.Boolean
>     java.lang.Character
>     java.util.Optional
>     java.lang.Number
>     java.lang.Record
> 
> 
> These value classes are loaded only if --enable-preview is set.    All valhalla tests should have preview enabled to ensure testing with the proper set of library classes.
> 
> Testing: Run `jdk_valhalla` and `hotspot_valhalla_runtime` with  `-Xint` with and without `--enable-preview`.  The result is pretty good.  [JDK-8327637](https://bugs.openjdk.org/browse/JDK-8327637) and [JDK-8327639](https://bugs.openjdk.org/browse/JDK-8327639) need further investigation.

https://bugs.openjdk.org/browse/JDK-8327481 can be closed as a duplicate of this.

make/modules/java.base/gensrc/GensrcValueClasses.gmk line 39:

> 37:     java/lang/Character.java \
> 38:     java/lang/Number.java \
> 39:     java/lang/Record.java \

Record is already included in the end of the list.

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PR Review: https://git.openjdk.org/valhalla/pull/1040#pullrequestreview-1923896364
PR Review Comment: https://git.openjdk.org/valhalla/pull/1040#discussion_r1517073698