RFR: 8252981: ObjectMonitor::object() cleanup changes extracted from JDK-8247281 [v3]

[Daniel D.Daugherty]

> This is a trivial review request. This changeset was tested with Mach5 Tier[1-3],4,5,6,7,8
> testing along with JDK-8252980 and JDK-8247281.
> 
> Since Erik and I are both contributors, we will need one other reviewer.
> 
> This sub-task is tracking ObjectMonitor::object() cleanup changes
> extracted from Erik's work on JDK-8247281. This extraction is done
> to ease the code review for the JDK-8247281 changes.
> 
> Here's the core cleanup:
> 
> diff -r fd7f6a424cd1 src/hotspot/share/runtime/objectMonitor.hpp
> --- a/src/hotspot/share/runtime/objectMonitor.hpp Fri Aug 28 16:43:09 2020 -0400
> +++ b/src/hotspot/share/runtime/objectMonitor.hpp Wed Sep 02 17:22:56 2020 -0400
> @@ -328,9 +328,9 @@
> 
>   public:
> 
> - void* object() const;
> - void* object_addr();
> - void set_object(void* obj);
> + oop object() const;
> + oop* object_addr();
> + void set_object(oop obj);
>    void release_set_allocation_state(AllocationState s);
>    void set_allocation_state(AllocationState s);
>    AllocationState allocation_state() const;
> 
> and those type changes ripple into the other files.
> 
> Note: The type for the ObjectMonitor::_object field is intentionally not
> being changed from "void*" in this changeset. That will be done in JDK-8247281.

Daniel D. Daugherty has updated the pull request with a new target base due to a merge or a rebase. The pull request
now contains three commits:

 - Merge branch 'master' into JDK-8252981
 - Remove left over setting of GVars.stw_random; fixed separately via JDK-8252126.
 - 8252981: ObjectMonitor::object() cleanup changes extracted from JDK-8247281

-------------

Changes: https://git.openjdk.java.net/jdk/pull/114/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=114&range=02
  Stats: 44 lines in 8 files changed: 0 ins; 0 del; 44 mod
  Patch: https://git.openjdk.java.net/jdk/pull/114.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/114/head:pull/114

PR: https://git.openjdk.java.net/jdk/pull/114