RFR(s): 8247248: JVM TI might create JNI locals in another thread when using handshakes.

[Robbin Ehn]

Hi David,
> Honestly I think I'd like to see things reverted to the use of 
> calling_thread as done for the VMOperation previously. We know it is 
> functionally correct and it should also have the same performance profile.

Ok, sure. But I don't have time to do that before fork.
I'll fix that in 16 and backport to 15.

Thanks, Robbin

> 
> Thanks,
> David
> 
>> Thanks, Robbin
>>
>>>
>>> Thanks,
>>> David
>>> -----
>>>
>>>> Issue:
>>>> https://bugs.openjdk.java.net/browse/JDK-8247248
>>>>
>>>> Local testing of JDI/JVMTI and t1-5.
>>>> (no real crash so there is nothing to reproduce)
>>>>
>>>> Thanks, Robbin