RFR: 8340205: Native linker allows MemoryLayout consisting of only PaddingLayout [v6]

[Per Minborg]

On Mon, 14 Oct 2024 12:45:36 GMT, Per Minborg <pminborg at openjdk.org> wrote:

>> This PR prevents sequence layout with padding to be used with the Linker.
>
> Per Minborg 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 13 additional commits since the last revision:
> 
>  - Update Linker docs
>  - Merge branch 'master' into linker-padding-layout-only
>  - Reword doce
>  - Add to specification and refine detection of PL GLs
>  - Add specific message for group layouts with only padding layouts
>  - Merge branch 'master' into linker-padding-layout-only
>  - Check exception message
>  - Remove redundant doc section
>  - Merge branch 'master' into linker-padding-layout-only
>  - Improve excception message
>  - ... and 3 more: https://git.openjdk.org/jdk/compare/85dcde52...b5e795f3

Should we disallow sequence layouts with an element count of zero?

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PR Comment: https://git.openjdk.org/jdk/pull/21041#issuecomment-2443804515