RFR: [8u] Bulk backports to sh/jdk8u

[Roman Kennke]

Am 16.01.2018 um 00:10 schrieb Aleksey Shipilev:
> http://cr.openjdk.java.net/~shade/shenandoah/backports/jdk8u-20180116/webrev.01/
> 
> This backports all outstanding work to sh/jdk8u. This passes a few nightlies in sh/jdk10. Some
> changes, notably moving the VM operations around required some fiddling to match the code in sh/jdk8u.
> 
> Changes include:
> 
>   [backport] Increase test timeouts
>   [backport] Report fwdptr size in JNI GetObjectSize
>   [backport] Disable verification from non-Shenandoah VMOps.
>   [backport] Cleanup reset_{next|complete}_mark_bitmap
>   [backport] Verifier should check klass pointers before attempting to reach for object size
>   [backport] TestSelectiveBarrierFlags times out due to too aggressive compilation mode
>   [backport] Shenandoah SA implementation
>   [backport] Allow use of fp spills around write barrier
>   [backport] Rehash VMOperations and cycle driver mechanics for consistency
>   [backport] Minor cleanup, uses latest Atomic API
>   [backport] Match barrier fastpath checks better
>   [backport] ShenandoahWriteBarrierRB flag to conditionally disable RB on WB fastpath
> 
> NIO checkIndex fix, and assorted Windows compilation fixes were already
> backported by Zhengyu and Roman.
> 
> Testing: hotspot_gc_shenandoah {fastdebug|release}, some benchmarks
> 
> Thanks,
> -Aleksey
> 

Looks good to me. Can't say for sure about C2 changes.

Roman