RFR [9]: Bulk backport to sh/jdk9

[Aleksey Shipilev]

On 12/04/2017 09:28 PM, Aleksey Shipilev wrote:
> http://cr.openjdk.java.net/~shade/shenandoah/backports/jdk9-20171204/webrev.01/
> 
> Weekend runs for sh/jdk10 seem fine.
> 
> Changes:
> 
> rev 13746 : [backport] Assert Shenandoah-specific safepoints instead of generic ones
> rev 13747 : [backport] Generic verification is possible only at Shenandoah safepoints
> rev 13748 : [backport] C2 should use heapword-sized object math
> rev 13749 : [backport] Trim/expand test heap sizes to fit small heaps
> rev 13750 : Add missing TestShenandoahWithLogLevel test
> rev 13751 : [backport] Report illegal transitions verbosely, and remove some no-op transitions
> rev 13752 : [backport] Cleanup and refactor Full GC code
> rev 13753 : [backport] Humongous regions should support explicit pinning
> rev 13754 : [backport] Eagerly drop CSet state from regions during Full GC
> rev 13755 : [backport] Region sampling should lock while gathering region data
> rev 13756 : [backport] Full GC should compact humongous regions
> rev 13757 : [backport] Rework shared bool/enum flags with proper types and synchronization
> ----- weekend runs tested up to here -----
> rev 13758 : [backport] Account trashed regions from coalesced CM-with-UR
> rev 13759 : [backport] ShenandoahVerifyOptoBarriers should not fail with disabled barriers
> ----- nightlies are testing now up to here -----

Nightlies are fine.

When backporting to sh/jdk8u, I discovered a small omission in arguments.cpp/r13759 -- missing
ShenandoahWriteBarrier check. Fixed here:
  http://cr.openjdk.java.net/~shade/shenandoah/backports/jdk9-20171204/webrev.02/

-Aleksey