RFR: Break heuristics out from ShCollectorPolicy into their own source files

[Zhengyu Gu]

Yes, I like this cleanup!

-Zhengyu

On 05/07/2018 04:22 PM, Roman Kennke wrote:
> Another one that I wanted to do since a long time, and which now is
> needed in preparation for the interleaving of minor/major GC change.
> 
> - Break out all the heuristics into their own source files
> - split declarations from definitions into .hpp/.cpp files
> 
> 
> This was a pretty mechanic refactoring, no logic changes (hopefully).
> 
> http://cr.openjdk.java.net/~rkennke/shheuristics/webrev.00/
> 
> Tested: building release/fastdebug PCH/no-PCH, hotspot_gc_shenandoah
> 
> Ok?
> 
>