RFR: 8244817: Add configuration logging similar to ZGCs to other GCs

Wed May 20 21:46:02 UTC 2020

> On May 18, 2020, at 1:56 PM, stefan.johansson at oracle.com wrote:
> 
> Hi,
> 
> Please review this enhancement to improve startup logging for G1, Parallel and Serial.
> 
> Webrev: http://cr.openjdk.java.net/~sjohanss/8244817/00/
> Issue: https://bugs.openjdk.java.net/browse/JDK-8244817

+1 for s/InitLogger/GCInitLogger/

Other than that, I think it looks good.