RFR: Verify fwdptr accesses during Full GC moves

[Roman Kennke]

Am 14.11.2017 um 22:03 schrieb Aleksey Shipilev:
> http://cr.openjdk.java.net/~shade/shenandoah/verify-fullgc-moves/webrev.01/
>
> This is the follow-up for the failures we have seen today around C1 compiler bugs. Verifier should
> capture them more consistently by verifying that no fwdptr access is observing the bad pointers
> during Full GC moves.
>
> Testing: hotspot_gc_shenandoah, + reverting the compiler workaround and observing the failure
>
> Thanks,
> -Aleksey
>
ok, this seems very useful.

I am trying to think of something more general (like, catch all any 
naked oop access during safepoint), but cannot easily come up with 
something concrete.

Roman