RFR: JDK-8237780: Shenandoah: More reliable nmethod verification

[Roman Kennke]

>> http://cr.openjdk.java.net/~rkennke/JDK-8237780/webrev.01/
> 
> This is fine.
> 
> Although I would probably be open for storing that diagnostics into stringStream (see how
> ShenandoahAsserts::print_failure does it), and putting it into the fatal message itself. Pros:
> customers would hand over hs_errs to us with the relevant diagnostics. Cons: we can overflow the
> stringStream and truncate parts of the data. Your call.


Ok, let's do that then:

http://cr.openjdk.java.net/~rkennke/JDK-8237780/webrev.02/

Good?

Roman