hg: jdk/sandbox: 8211270: GC abstraction to get real object and headers size

[chris.hegarty at oracle.com]

Changeset: c4a39588a075
Author:    rkennke
Date:      2018-10-10 10:58 +0200
URL:       http://hg.openjdk.java.net/jdk/sandbox/rev/c4a39588a075

8211270: GC abstraction to get real object and headers size
Reviewed-by: shade, zgu, eosterlund

! src/hotspot/share/gc/shared/collectedHeap.cpp
! src/hotspot/share/gc/shared/collectedHeap.hpp
! src/hotspot/share/prims/jvmtiEnv.cpp
! src/hotspot/share/prims/whitebox.cpp