RFR: Enable string deduplication in all marking phases

[Aleksey Shipilev]

On 10/02/2018 08:29 PM, Zhengyu Gu wrote:
> Webrev: http://cr.openjdk.java.net/~zgu/shenandoah/dedup_all_phases/webrev.01/

Thanks! Looks good. Yes, missing String candidates from code roots is a lesser evil.

Thanks,
-Aleksey