RFR: 8339132: Make DirectCodeBuilder write through without allocating instruction objects [v3]

[Adam Sotona]

On Wed, 28 Aug 2024 21:14:50 GMT, Chen Liang <liach at openjdk.org> wrote:

>> Make `DirectCodeBuilder` write instructions actually directly without allocating extra objects. This speed up a lot of simple Class-File building cases that never go through intermediate transforms.
>
> Chen Liang has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains five additional commits since the last revision:
> 
>  - Remove redundant qualification, avoid boxing in b/sipush validation
>  - Merge branch 'master' of https://github.com/openjdk/jdk into exp/cob-direct-methods
>  - Use uppercase L for long literals
>    
>    Co-authored-by: Andrey Turbanov <turbanoff at gmail.com>
>  - Moar fixes
>  - More direct code builder

Looks good to me.

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Marked as reviewed by asotona (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/20738#pullrequestreview-2267897550