RFR: Roots verification should take the special roots first

[Aleksey Shipilev]

On 02/16/2018 06:34 PM, Aleksey Shipilev wrote:
> http://cr.openjdk.java.net/~shade/shenandoah/verifier-roots-threadlast/webrev.01/
> 
> The motivation is in code comment. Need this to debug a failure in sh/jdk8u.

Ping.

-Aleksey