8202377: Modularize C2 GC barriers

[Erik Österlund]

Hi Roland,

Thank you for the review. :)

/Erik

On 2018-05-17 15:50, Roland Westrelin wrote:
>> http://cr.openjdk.java.net/~eosterlund/8202377/webrev.02/
> That looks good to me.
>
> Roland.