RFR: 8231996: ZGC: Replace ZStatisticsForceTrace with check if JFR event is enabled

[Per Liden]

Thanks Erik!

/Per

On 10/16/19 9:19 AM, Erik Osterlund wrote:
> Hi Per,
> 
> Looks good.
> 
> Thanks,
> /Erik
> 
>> On 10 Oct 2019, at 12:28, Per Liden <per.liden at oracle.com> wrote:
>>
>> Remove and replace the diagnostic flag ZStatisticsForceTrace with a check if JFR event is enabled. This flag was introduced as a safety measure back when sending JFR events was problematic in some contexts. This is no longer the case, so we can just let the default.jfc/profile.jfc control when those events should be sent.
>>
>> Bug: https://bugs.openjdk.java.net/browse/JDK-8231996
>> Webrev: http://cr.openjdk.java.net/~pliden/8231996/webrev.0
>>
>> /Per
>