RFR: Bulk backport to sh/jdk8u

[Aleksey Shipilev]

http://cr.openjdk.java.net/~shade/shenandoah/backports/jdk8u-20171003/webrev.01/

This backports recent work from sh/jdk10 to sh/jdk8u repository. The changes include the last
retracted backport, plus new work. This patch queue includes the PLL OOME fix, otherwise tests
intermittently timeout. That fix has its own RFR, and shall be committed before this bulk backport.

Changes:

rev 10119 : OOME in SurrogateLockerThread deadlocks the GC cycle
rev 10120 : [backport] Verify regions status
rev 10121 : [backport] Asynchronous region recycling
rev 10122 : [backport] Heap region sampling should publish region states
rev 10123 : [backport] Store checks should run most of the time
rev 10124 : [backport] FreeSet refactor: bitmaps, cursors, biasing
rev 10125 : [backport] Trim the TLAB sizes to avoid wasteful retirement under TLAB races
rev 10126 : [backport] Adaptive collection set selection in adaptive policy
rev 10127 : [backport] Make heap counters update completely asynchronous
rev 10128 : [backport] Adaptive heuristics accounts trashed cset twice
rev 10129 : [backport] Ensure tasks use correct number of workers
rev 10130 : [backport] Dynamic worker refactoring
rev 10131 : [backport] Refactoring GC phase and heap allocation tracking out of policy
rev 10132 : [backport] Refactor worker timings into ShenandoahPhaseTimings
rev 10133 : [backport] fix TCK crash with shenandoah
rev 10134 : [backport] When Shenandoah WB is moved out of loop, connect it to correct loop memory
Phi (back out and revisit previous fix)
rev 10135 : [backport] Add comments in shenandoah_store_check on direct heap field use
rev 10136 : [backport] AArch64 shenandoah_store_check should read evacuation_in_progress as byte

I need sign-offs from Zhengyu and Roland, at least for their respective changes.

Testing:
  - hotspot_gc_shenandoah/fastdebug at every revision
  - hotspot_gc_shenandoah/{fastdebug,release} for complete patch queue
  - jcstress/fastdebug -m quick for complete patch queue

Thanks,
-Aleksey