RFR: Fix CAS-obj with expected=NULL

[Roman Kennke]

Am 11.07.2018 um 16:58 schrieb Roland Westrelin:
> 
>> http://cr.openjdk.java.net/~rkennke/fix-cas-obj-null/webrev.00/
> 
> That's not right. Matching introduces Binary nodes:
> 
>       case Op_CompareAndSwapN: {   // Convert trinary to binary-tree
>         Node *newval = n->in(MemNode::ValueIn );
>         Node *oldval  = n->in(LoadStoreConditionalNode::ExpectedIn);
>         Node *pair = new BinaryNode( oldval, newval );
>         n->set_req(MemNode::ValueIn,pair);
>         n->del_req(LoadStoreConditionalNode::ExpectedIn);
> 
> so index of inputs changes and existing code is good.

OMG, ok. Thank you!

Roman