- Unify AIX and Starboard wrapping code.
- Move all wrapping code into `platform/memory.h`

Change-Id: I42c04dd1e982edff2db7bbfa9eecdbdd67f40714
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3858226Reviewed-by: Jakob Linke <jgruber@chromium.org>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/main@{#82794}