RFR: 8366461: Remove obsolete method handle invoke logic [v3]

[Manuel Hässig]

On Tue, 2 Sep 2025 20:52:32 GMT, Dean Long <dlong at openjdk.org> wrote:

>> At one time, JSR292 support needed special logic to save and restore SP across method handle instrinsic calls, but that is no longer the case. The only platform that still does the save/restore is arm32, which is no longer necessary. The save/restore can be removed along with related APIs and logic. Note that the arm32 port is largely based on the x86 port, which stopped doing the save/restore in jdk9 ([JDK-8068945](https://bugs.openjdk.org/browse/JDK-8068945)).
>
> Dean Long has updated the pull request incrementally with three additional commits since the last revision:
> 
>  - revert whitespace change
>  - undo debug changes
>  - cleanup

Thank you for cleaning this up, @dean-long. I just have a drive-by comment.

src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/runtime/aarch64/AARCH64Frame.java line 372:

> 370:         // DEBUG_ONLY(verifyDeoptriginalPc(senderNm, raw_unextendedSp));
> 371:       }
> 372:     }

`<arch>Frame.java adjustUnextendedSP()` do not seem to do anything? Perhaps these could be cleaned up as well?

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PR Review: https://git.openjdk.org/jdk/pull/27059#pullrequestreview-3179245014
PR Review Comment: https://git.openjdk.org/jdk/pull/27059#discussion_r2317990499