RFR: 8246258: Enable hs_err heap printing earlier during initialization

[Stefan Karlsson]

Hi all,

Please review this patch to enable the hs_err GC / heap printing 
directly after the heap has been set up.

https://cr.openjdk.java.net/~stefank/8246258/webrev.01/
https://bugs.openjdk.java.net/browse/JDK-8246258

Changes in the patch:
- Remove the Universe::is_fully_initialized
- Add NULL initializations and checks in print paths

I tested this patch by adding a temporary fatal(...) here:

jint Universe::initialize_heap() {
   assert(_collectedHeap == NULL, "Heap already created");
   _collectedHeap = GCConfig::arguments()->create_heap();
   // <<<< HERE
   log_info(gc)("Using %s", _collectedHeap->name());
   return _collectedHeap->initialize();
}

and manually looking at the result when running with all GCs. Will run 
this through tier1-3.

Thanks,
StefanK