[28] JEP 541: Deprecate the macOS/x64 Port for Removal

ref: https://openjdk.org/jeps/541

Summary
Deprecate the macOS/x64 port, with the intent to remove it in a future release, in order to reduce maintenance costs.

Note: should not affect - investigate.

Start with the linked JEP 541 and inspect the Eclipse JDT Core code and build or platform configuration for macOS/x64 references. Determine whether deprecating that Java port affects this repository, and document or test the finding; the issue is done when the impact is established and any required follow-up is identified.

Written by the indexing model from the issue text.