RFR: 8325194: GHA: Add macOS M1 testing [v5]

[Magnus Ihse Bursie]

On Sat, 3 Feb 2024 21:55:25 GMT, George Adams <gdams at openjdk.org> wrote:

>> Now that macOS M1 executors are [available in GitHub actions](https://github.blog/changelog/2024-01-30-github-actions-introducing-the-new-m1-macos-runner-available-to-open-source/) it makes sense to move the build to run on M1 (rather than cross-compiled) and also enable testing on the platform.
>
> George Adams has updated the pull request incrementally with one additional commit since the last revision:
> 
>   simplify jtreg

Looks fine, I guess. Replacing one cross-compilation with native build is OK. 

Adding the testing is... well, I guess it is reasonable given the popularity of macosx-aarch64, but note that it will add to the creeping increase in the github test suite. At some point, we will only be able to add more testing if we remove some existing.

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Marked as reviewed by ihse (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/17694#pullrequestreview-1865047739