RFR: Add support for building on AArch64

[Per Liden]

On 10/31/19 12:01 PM, Nick Gasson wrote:
> Hi,
> 
> What's the workflow for make changes to the PR? (the Mac build broke.) 
> Should I amend the commit and force-push or add another commit to that 
> branch?
> 
>>   Webrev: https://webrevs.openjdk.java.net/skara/231/webrev.00
> 
> This 404s for me - is that a known issue?

Hmm, works fine for me.

cheers,
Per