RFR (S) 8230024: Shenandoah: remove unnecessary ShenandoahTimingConverter

[Roman Kennke]

Looks ok to me. Let Zhengyu also look at it.

Thanks,
Roman


> RFE:
>   https://bugs.openjdk.java.net/browse/JDK-8230024
> 
> Webrev:
>   https://cr.openjdk.java.net/~shade/8230024/webrev.01/
> 
> This is not used, and it is the source of many build failures when WeakProcessor and OopStorage
> shapes change a lot. Should be removed for clarity. This blocks the fix for JDK-8229998. I believe
> this one should go in separately to be backportable.
> 
> Testing: hotspot_gc_shenandoah {fastdebug|release}, grepping around the source code
>