RFR: 8329545: [s390x] Fix garbage value being passed in Argument Register [v2]

[Martin Doerr]

On Wed, 3 Apr 2024 15:10:25 GMT, Sidraya Jayagond <sjayagond at openjdk.org> wrote:

>> Fix sign extension on 4 byte load from argument stack slot to GPR.
>
> Sidraya Jayagond has updated the pull request incrementally with one additional commit since the last revision:
> 
>   copyright header

LGTM.

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Marked as reviewed by mdoerr (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/18601#pullrequestreview-1991083800