hg: jdk/hs: 8194406: Use Atomic::replace_if_null

[kim.barrett at oracle.com]

Changeset: 51825789dd89
Author:    kbarrett
Date:      2018-01-04 18:18 -0500
URL:       http://hg.openjdk.java.net/jdk/hs/rev/51825789dd89

8194406: Use Atomic::replace_if_null
Reviewed-by: coleenp, dholmes

! src/hotspot/share/code/nmethod.cpp
! src/hotspot/share/gc/parallel/gcTaskThread.cpp
! src/hotspot/share/oops/method.cpp
! src/hotspot/share/prims/jvmtiRawMonitor.cpp
! src/hotspot/share/runtime/mutex.cpp
! src/hotspot/share/runtime/objectMonitor.cpp
! src/hotspot/share/runtime/synchronizer.cpp
! src/hotspot/share/services/mallocSiteTable.cpp
! src/hotspot/share/utilities/bitMap.cpp