RFR: Refactor uncommit handling: react on explicit GCs, feature kill flag, etc

[Roman Kennke]

Looks good!

On Fri, Mar 2, 2018 at 1:11 PM, Aleksey Shipilev <shade at redhat.com> wrote:
> http://cr.openjdk.java.net/~shade/shenandoah/refactor-uncommit/webrev.01/
>
> This refactors uncommit handling:
>  - There is now a global option that disables uncommit: no need to set large delay to disable, which
> also unties interaction between delay and AlwaysPreTouch;
>  - Explicit GC (e.g. System.gc()) now uncommits everything: user wants the memory, user gets it
> without delay;
>  - Flag renames to group everything under ShenandoahUncommit
>
> Testing: hotspot_gc_shenandoah
>
> Thanks,
> -Aleksey
>