Replace MemBarRelease for final field write with MemBarStoreStore

[Andrew Haley]

On 09/02/2015 02:55 PM, Vitaly Davidovich wrote:
>     Probably not.  See http://www.hboehm.info/c++mm/no_write_fences.html
>     for an explanation.
> 
> Is that really relevant to final/stable field writes though?

I believe so.  See also http://shipilev.net/blog/2014/all-fields-are-final/,
"Implementation Support"

Andrew.