RFR: Don't check store value in Shenandoah C2 verifier

[Aleksey Shipilev]

On 2/18/19 5:50 PM, Roman Kennke wrote:
>>> Here comes the real fix: CreateEx nodes don't require a barrier (the
>>> exception is either new, or one of the pre-generated exceptions that we
>>> keep guaranteed in to-space), and the verifier needs to be extended for
>>> this:
>>>
>>> http://cr.openjdk.java.net/~rkennke/fixoptoverifier/webrev.01/
>>
>> Patch looks okay.
>>
>> But let me ask this: the same must be true for our mainline non-LRB Shenandoah too? If so, why
>> verification started to fail only with LRB?
> 
> I believe we don't guarantee to-spaciness on pre-generated exceptions
> pre-LRB, and thus always generated (or did not elide) barriers.

Okay, that makes sense. Looks good!

-Aleksey