RFR (S): "passive" heuristics

[Aleksey Shipilev]

Hi,

In order to performance test Full GC phase reliably, I need a policy
that does not do any concurrent GCs whatsoever, and instead relies on
full GCs alone.

"passive" heuristics:
  http://cr.openjdk.java.net/~shade/shenandoah/passive-heuristics/webrev.01/

Ok?

-Aleksey