RFR: 8235654: JFR leak profiler should not trace through the StringTable

[Erik Österlund]

Hi Erik,

Thanks for the review!

/Erik

> On 10 Dec 2019, at 20:17, Erik Gahlin <erik.gahlin at oracle.com> wrote:
> 
> 
> Thanks for fixing this. 
> 
> When we implemented the feature we were not able figure out what roots we really needed to walk (and in what order).
> 
> Looks good.
> 
> Erik
> 
> On 2019-12-10 17:22, erik.osterlund at oracle.com wrote:
>> Hi,
>> 
>> The JFR leak profiler finds strong reference chains to object samples. Weirdly enough, it walks the StringTable roots. But these oops are phantomly reachable. So they should arguably be excluded from the root snapshot. This incorrect use of StringTable::oops_do is the only use of StringTable::oops_do, so I'm removing that function.
>> 
>> Bug:
>> https://bugs.openjdk.java.net/browse/JDK-8235654
>> 
>> Webrev:
>> http://cr.openjdk.java.net/~eosterlund/8235654/webrev.00/
>> 
>> Thanks,
>> /Erik