RFR [10]: Revert "improved profiled predicates"

[Roland Westrelin]

> http://cr.openjdk.java.net/~shade/shenandoah/10-revert-improved-predicates/webrev.01/
>
> sh/jdk10 is now our backports repository, and it should not have things that we are upstreaming. One
> of those things is "improved profiled predicates" that Roland pushed recently:
>   http://hg.openjdk.java.net/shenandoah/jdk10/rev/279bd9767680
>
> Among other things, it has some bugs:
>   http://mail.openjdk.java.net/pipermail/shenandoah-dev/2018-February/004936.html

Ok.

Roland.