Backports to sh/jdk1 2019-03-18

[Aleksey Shipilev]

On 3/18/19 9:26 PM, Roman Kennke wrote:
> Full webrev:
> http://cr.openjdk.java.net/~rkennke/backports-jdk11-2019-03-18/webrev.00/

Looks good.

*) I checked that +UseTransparentHugePages and +UseLargePages work fine on my examples.

*) Also diff'ed ShenandoahHeap::initialize with jdk12 version, and there is a teeny-tiny difference
here:

 141   size_t init_byte_size = collector_policy()->initial_heap_byte_size();
 142   size_t max_byte_size = collector_policy()->max_heap_byte_size();
 143   size_t heap_alignment = collector_policy()->heap_alignment();

L142 is aligned by "=" in jdk12 and jdk/jdk.

*) This line should probably be moved from "Figure out heap sizing" block to "Initialize the rest of
GC subsystems". hotspot_gc_shenandoah has to pass after this move :)

 152   BarrierSet::set_barrier_set(new ShenandoahBarrierSet(this));

Thanks,
-Aleksey