[aarch64-port-dev ] Shenandoah import (2nd attempt)

[Andrew Haley]

On 04/29/2016 02:51 PM, Roman Kennke wrote:
> Please review and commit if you find it ok.

Will do.  BTW, it always helps if you send this as a real webrev from a
commit; that way the author is set and so is the comment.

Andrew.