RFR: 8215451: JNI IsSameObject should not keep objects alive

[Per Liden]

On 12/17/18 3:58 PM, Per Liden wrote:
[...]
>> I was going to suggest the explicit 0 decorator values seemed like an
>> abstraction violation, and should instead be using the named "empty"
>> decorator value. But I see that's called "INTERNAL_EMPTY". That seems
>> like a (separate) bug.
>>
> 
> I had the exact same thought and I talked to Erik about it. We agreed 
> that we should rename INTERNAL_EMPTY to something less "internal". How 
> about DECORATORS_NONE?
> 

Filed https://bugs.openjdk.java.net/browse/JDK-8215492

It's a 1 minute job to fix, once we agree on a new name for it. Feel 
free to make suggestions. DECORATORS_NONE is the best I've come up with 
so far, but I'm open to suggestions.

cheers,
Per