8230392: Define AArch64 as MULTI_COPY_ATOMIC

[David Holmes]

On 24/01/2020 7:06 pm, Andrew Haley wrote:
> On 1/23/20 10:41 PM, David Holmes wrote:
>> This does make me wonder whether other lock-free code in the VM needs
>> special handling for non-CPU_MULTI_COPY_ATOMIC ??
> 
> I don't think we should do exactly that. I would have thoght that
> where an algorithm needs anything stronger than acquire/release
> consistency we should use explicit sequentially-consistent loads and
> stores.

What I meant was, "I wonder whether other lock-free code in the VM is 
assuming multi-copy-atomicity?".

David