[lworld] RFR: 8348904: [lworld] Remove concept of default value object and zeroInstance [v2]

[Chen Liang]

On Mon, 3 Feb 2025 03:14:15 GMT, Roger Riggs <rriggs at openjdk.org> wrote:

>> Remove support for the default value object and zeroInstance, no longer included in the spec.
>> In related tests, test cases were removed if no longer applicable or replaced by a hand created zero/null object.
>
> Roger Riggs has updated the pull request incrementally with three additional commits since the last revision:
> 
>  - Remove debug println
>  - Merge branch 'xx-broken-default-value-object' into 8348904-remove-default-value-object
>    Remove vestigal remains of zeroInstance in DirectMethodHandle.makePreparedFieldLambdaForm.
>  - 8348904: [lworld] Remove concept of default value object and zeroInstance
>    Remove support for the default object and zeroInstance, no longer included in the spec.
>    In related tests, test cases were removed if no longer applicable or
>    replaced by a hand created zero/null object.

We can clean up the implicitly constructable concept from the VM and arrays later.

src/java.base/share/classes/jdk/internal/misc/Unsafe.java line 2:

> 1: /*
> 2:  * Copyright (c) 2000, 2025, Oracle and/or its affiliates. All rights reserved.

Thanks for this update; thought we don't update headers in valhalla.

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Marked as reviewed by liach (no project role).

PR Review: https://git.openjdk.org/valhalla/pull/1346#pullrequestreview-2588878007
PR Review Comment: https://git.openjdk.org/valhalla/pull/1346#discussion_r1938752926