[foreign-memaccess+abi] RFR: 8299911: Refactor struct handling in AArch64 CallArranger [v3]

[Maurizio Cimadamore]

On Wed, 11 Jan 2023 13:48:31 GMT, Jorn Vernee <jvernee at openjdk.org> wrote:

>> Only HFAs are handled in this field-wise manner (see the table in the comment on this method as well). The assumption is that any struct with padding doesn't get classified as an HFA (and they don't in the current code), and we can not get here (see also [`jdk.internal.foreign.abi.aarch64.TypeClass::isHomogeneousFloatAggregate`](https://github.com/openjdk/panama-foreign/blob/08225e4f5e00837e974098a933f27267f3c0dbc5/src/java.base/share/classes/jdk/internal/foreign/abi/aarch64/TypeClass.java#L61-L91)). But, since this is a non-local assumption, I added a comment as well.
>
> I've attempted to clarify the comment once more.

Ok, the main issue was that by the time I got there I lost track of "isFieldWise implies HFA"

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

PR: https://git.openjdk.org/panama-foreign/pull/765