[15] RFR 8244821: Shenandoah: disarmed_value is initialized at wrong place

[Zhengyu Gu]

Aleksey discovered that JDK-8244328 changed where disarmed_value is set, 
which may cause nmethod entry barrier to see wrong disarmed value.

Bug: https://bugs.openjdk.java.net/browse/JDK-8244821
Webrev: http://cr.openjdk.java.net/~zgu/JDK-8244821/webrev.00/index.html

Test:
   hotspot_gc_shenandoah


Thanks,

-Zhengyu