[aarch64-port-dev ] RFR: 8224187 Refactor arraycopy_prologue to allow ZGC read barriers on arraycopy

[Roman Kennke]

I'd rather see Erik's proposal implemented to make the GC generate the
whole path to begin with. Otherwise we'd band-aid for ZGC now, and later
have to band-aid again for Shenandoah. See discussion for JDK-8223240
and in your aarch64 on ZGC thread.

Roman

> Hello,
>    On aarch64 the signature for
> barrierSetAssembler::arraycopy_prologue needs to be changed in order
> accept the source as well as the destination array for ZGC's barriers.
> 
> The bug:
>  https://bugs.openjdk.java.net/browse/JDK-8224187
> and the patch:
>   http://cr.openjdk.java.net/~smonteith/8224187/webrev.0/
> 
> 
> BR,
>    Stuart
>