RFR: Speed up asserts and verification, improve fastdebug builds performance

[Roman Kennke]

Great! Go!

On Mon, Feb 26, 2018 at 6:46 PM, Aleksey Shipilev <shade at redhat.com> wrote:
> http://cr.openjdk.java.net/~shade/shenandoah/assert-perf/webrev.01/
>
> This substantially improves ShenandoahAsserts performance, which translates to more GC cycles for
> time-bound aggressive tests, and faster work-bound tests. This is achieved by carefully reshuffling
> assert paths to avoid double/triple checks.
>
> GCBasher/aggressive does 2x more GC cycles per minute with this patch.
> hotspot_gc_shenandoah improves from 38 minutes to 26 minutes on my desktop.
>
> Testing: hotspot_gc_shenandoah (fastdebug), hotspot_fast_gc_shenandoah (fastdebug|release)
>
> Thanks,
> -Aleksey
>