[8u] RFR 8277224: sun.security.pkcs.PKCS9Attributes.toString() throws NPE

[Zhengyu Gu]

> 
> This webrev still seems to be based on the old 8u repositories.
> 
> Changes now need to be against https://hg.openjdk.java.net/jdk8u/monojdk8u-dev

Rebased: http://cr.openjdk.java.net/~zgu/JDK-8277224-8u/webrev.01/

Thanks,

-Zhengyu

> 
> Thanks,
>