RFR [sh/8u]: Correct order between load, LRB and membar nodes

[Roman Kennke]

>> Right. That is a problem. Let's do something else then:
>> http://cr.openjdk.java.net/~rkennke/lrb-membars/webrev.01/
>>
>> This extracts the original load from the LRB before feeding into the membar.
> 
> Um, no. This applies LRB only when is_volatile is true, which is obviously incorrect.
> 
> Don't we need to feed the LRB result to set_result too? Or is it handled in some non-obvious way?

We do. And we also feed the LRB into the pre-barrier and into
set_result(). We only extract the original load in order to feed it into
the membar.

Roman