RFR: 8316046: x64 platforms unecessarily save xmm16-31 when UseAVX >= 3

[Daniel Jeliński]

On Mon, 23 Oct 2023 11:37:08 GMT, Jorn Vernee <jvernee at openjdk.org> wrote:

> See JBS issue. We don't need to save xmm16+ on x64 platforms (which are currently saved in FFM upcall stubs). This is achieved simply by adding these registers to the volatile register lists of both ABIs.
> 
> Related: https://github.com/openjdk/jdk/pull/15688
> 
> Testing: `jdk_foreign`

Marked as reviewed by djelinski (Reviewer).

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PR Review: https://git.openjdk.org/jdk/pull/16307#pullrequestreview-1692717476