RFR: 8367532: Declare all stubgen stub entries including internal cross-stub entries

[Ashutosh Mehra]

On Thu, 11 Sep 2025 15:13:07 GMT, Andrew Dinn <adinn at openjdk.org> wrote:

> This PR adds declarations for internal entries used to daisy chain memory copy stubs and ensures they are saved to generated fields when produced and accessed via those fields when consumed. This will ensure they are saved and restored correctly when stubgen blobs are included in the AOT Code Cache.
> 
> The PR also fixes a few AArch64 stubs which do not currently have their first entry at offset 0, another thing that will be needed to simplify AOT Code cache save and restore.

x86 and aarch64 changes look fine to me.

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Marked as reviewed by asmehra (Committer).

PR Review: https://git.openjdk.org/jdk/pull/27228#pullrequestreview-3230511707