RFR: 8334137: Marlin: replace sun.misc.Unsafe memory access methods with FFM [v8]

[Kevin Rushforth]

On Wed, 11 Jun 2025 17:52:18 GMT, Andy Goryachev <angorya at openjdk.org> wrote:

>> Although... there is only one use now of the default constructor, so it would be trivial to change it and dispense with the first constructor.
>
> it's a minor thing;  we could do it later if you plan a follow-up - I more dislike the idea of having an unused array...

I'll file a few cleanup bugs before I integrate and note them in comments.

-------------

PR Review Comment: https://git.openjdk.org/jfx/pull/1814#discussion_r2140840593