Fix instruction removal for 'as' test; the bug caused us to stop optimizing after an 'as' test.

runtime/vm/flow_graph_optimizer.cc

Index: runtime/vm/flow_graph_optimizer.cc
===================================================================
--- runtime/vm/flow_graph_optimizer.cc	(revision 31394)
+++ runtime/vm/flow_graph_optimizer.cc	(working copy)
@@ -3424,7 +3424,7 @@
       }
       // Remove call, replace it with 'left'.
       call->ReplaceUsesWith(left);
-      call->RemoveFromGraph();
+      current_iterator()->RemoveCurrentFromGraph();

[zra, 2013/12/27 21:10:06]

Many other uses of RemoveCurrentFromGraph() are preceded by an ASSERT checking
that the correct node will be removed from the graph. Would it make sense to do
something like that here, too? Would it make sense to ASSERT before
RemoveFromGraph(), as well, since removing the wrong node caused the problem
here?

[srdjan, 2013/12/27 21:35:01]

Good point, added the assert.

       return;
     }
   }