[11] 2019-10-16: Bulk backports to sh/jdk11

[Aleksey Shipilev]

https://cr.openjdk.java.net/~shade/shenandoah/backports/jdk11-20191016/webrev.01/

Anticipating the final push of 11.0.5 soon, these are some outstanding Shenandoah backports for soon
to be open sh/jdk11. I would obviously push this only after 11.0.5 merge lands. Reviews are
appreciated meanwhile anyway.

Changes:
  [backport] 8231946: Remove obsolete and unused ShenandoahVerifyObjectEquals flag
  [backport] 8231932: Shenandoah: conc/par GC threads ergonomics overrides user settings
  [backport] 8231667: Shenandoah: Full GC should take empty regions into slices for compaction
  [backport] 8230470: Shenandoah doesn't need change from JDK-8212610 anymore
  [backport] 8231947: Shenandoah: cleanup ShenandoahHumongousMoves flag treatment
  [backport] 8232176: Shenandoah: new assert in ShenandoahEvacuationTask is too strong
  [backport] 8232102: Shenandoah: print everything in proper units
  [backport] 8228369: Shenandoah: Refactor LRB C1 stubs
  [backport] 8229709: x86_32 build and test failures after JDK-8228369 (Shenandoah: Refactor LRB C1)
  [backport] 8229470: Shenandoah: Fix C1 getAndSetObject() failure
  [backport] 8229977: Shenandoah: save/restore FPU state aroud LRB runtime call

Testing: hotspot_gc_shenandoah {fastdebug, release} x {x86_64, aarch64}

-- 
Thanks,
-Aleksey