hg: jdk/submit: Merge

[zgu at redhat.com]

Changeset: 55b6e2c60dfc
Author:    zgu
Date:      2019-04-02 14:51 -0400
URL:       http://hg.openjdk.java.net/jdk/submit/rev/55b6e2c60dfc

Merge

! src/hotspot/share/gc/g1/g1ConcurrentMark.cpp
! src/hotspot/share/gc/shenandoah/shenandoahConcurrentMark.cpp