hg: jdk/submit: 8214202: DirtyCardQueueSet::get_completed_buffer should not clear _process_completed

[kim.barrett at oracle.com]

Changeset: e62fe5079d64
Author:    kbarrett
Date:      2018-11-26 13:17 -0500
URL:       http://hg.openjdk.java.net/jdk/submit/rev/e62fe5079d64

8214202: DirtyCardQueueSet::get_completed_buffer should not clear _process_completed
Summary: Remove flag clearing and simplify get_completed-buffer.
Reviewed-by: tschatzl, sjohanss

! src/hotspot/share/gc/g1/dirtyCardQueue.cpp
! src/hotspot/share/gc/shared/ptrQueue.cpp