hg: shenandoah/jdk: Fixed code roots scanning that might be bypassed during degenerated cycle

[zgu at redhat.com]

Changeset: 3b8adcca940c
Author:    zgu
Date:      2018-02-22 13:36 -0500
URL:       http://hg.openjdk.java.net/shenandoah/jdk/rev/3b8adcca940c

Fixed code roots scanning that might be bypassed during degenerated cycle

! src/hotspot/share/gc/shenandoah/shenandoahConcurrentMark.cpp
! src/hotspot/share/gc/shenandoah/shenandoahConcurrentMark.hpp