RFR: 7537: Build script assumes that Darwin always targets x86_64

[Marcus Hirt]

On Thu, 20 Jan 2022 10:38:35 GMT, Johannes Bechberger <duke at openjdk.java.net> wrote:

> Tested on Mac M1.

Marked as reviewed by hirt (Lead).

Olga helped verify this!

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

PR: https://git.openjdk.java.net/jmc/pull/366