RFR: Backout: Refactor evac-in-progress flag to more general gc-phase flag

[Aleksey Shipilev]

On 10/02/2017 04:06 PM, Roman Kennke wrote:
> This is a clean backout of the previous change "Refactor evac-in-progress flag to more general
> gc-phase flag". In discussions we came to the conclusion that we should leave that code as it was,
> and instead make new experimental code check for existing flags.
> 
> Ok to back out that change?
> 
> http://cr.openjdk.java.net/~rkennke/backout-gcflags/webrev.00/

*) This looks wrong, should be just cbz? If that was masked by the patch, it would be nice to fix it
up in another change after this backout.

(two places in current patch):
-  tbz(rscratch1, ShenandoahHeap::EVACUATION_BITPOS, done);
+  cbzw(rscratch1, done);

Otherwise looks good. Thanks for doing this!

-Aleksey