Add missing barrier in C1 NIOCheckIndex intrinsic

[Roman Kennke]

Am 21.12.2017 um 16:13 schrieb Aleksey Shipilev:
> On 12/21/2017 04:09 PM, Roman Kennke wrote:
>> We're missing a read-barrier in a C1 intrinsic for NIO checkIndex.
>>
>> This is the root cause for:
>> http://mail.openjdk.java.net/pipermail/shenandoah-dev/2017-December/004495.html
>>
>> This is the fix:
>> http://cr.openjdk.java.net/~rkennke/c1-missing-barrier/webrev.00/
> 
> This makes sense.
> 
> I just got home, and was meaning to write the regression test for it. Give me an hour?
>

Oh yes, that would be perfect!

Thanks,
Roma