RFR: ZGC: Revert VerifyFieldClosure change

[Per Liden]

Looks good.

/Per

On 2018-05-29 15:12, Stefan Karlsson wrote:
> Hi all,
> 
> This code was changed some time ago to fix verification failures when 
> running with fastdebug (-XX:+VerifyBeforeExit turned on). We have since 
> then disabled VerifyBeforeExit for ZGC, and this code can therefore be 
> reverted:
> 
> diff --git a/src/hotspot/share/oops/instanceKlass.cpp 
> b/src/hotspot/share/oops/instanceKlass.cpp
> --- a/src/hotspot/share/oops/instanceKlass.cpp
> +++ b/src/hotspot/share/oops/instanceKlass.cpp
> @@ -3212,11 +3212,7 @@
>   class VerifyFieldClosure: public OopClosure {
>    protected:
>     template <class T> void do_oop_work(T* p) {
> -    // This verification wants to see that all the oops are correct 
> without
> -    // first passing through a barrier. However, we need a barrier here 
> since
> -    // this can happen at shutdown before we've completed the remapping.
> -    // Revisit this later.
> -    oop obj = HeapAccess<>::oop_load(p);
> +    oop obj = RawAccess<>::oop_load(p);
>       if (!oopDesc::is_oop_or_null(obj)) {
>         tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p2i(p), 
> p2i(obj));
>         Universe::print_on(tty);
> 
> Thanks,
> StefanK