Revert "Remove SminessPropagator and FlowGraphTypePropagator and all associated infrastructure and …

runtime/vm/flow_graph_optimizer.h

Index: runtime/vm/flow_graph_optimizer.h
diff --git a/runtime/vm/flow_graph_optimizer.h b/runtime/vm/flow_graph_optimizer.h
index a0922ef211fb922d5b0607ca75c38bb332e25ab9..b53054e2f45b2f4bef6c74145ba5568059091282 100644
--- a/runtime/vm/flow_graph_optimizer.h
+++ b/runtime/vm/flow_graph_optimizer.h
@@ -121,6 +121,39 @@ class FlowGraphOptimizer : public FlowGraphVisitor {
 class ParsedFunction;
 
 
+class FlowGraphTypePropagator : public FlowGraphVisitor {
+ public:
+  explicit FlowGraphTypePropagator(FlowGraph* flow_graph)
+      : FlowGraphVisitor(flow_graph->reverse_postorder()),
+        parsed_function_(flow_graph->parsed_function()),
+        flow_graph_(flow_graph),
+        still_changing_(false) { }
+  virtual ~FlowGraphTypePropagator() { }
+
+  const ParsedFunction& parsed_function() const { return parsed_function_; }
+
+  void PropagateTypes();
+
+ private:
+  virtual void VisitBlocks();
+
+  virtual void VisitAssertAssignable(AssertAssignableInstr* instr);
+  virtual void VisitAssertBoolean(AssertBooleanInstr* instr);
+  virtual void VisitInstanceOf(InstanceOfInstr* instr);
+
+  virtual void VisitGraphEntry(GraphEntryInstr* graph_entry);
+  virtual void VisitJoinEntry(JoinEntryInstr* join_entry);
+  virtual void VisitPhi(PhiInstr* phi);
+  virtual void VisitParameter(ParameterInstr* param);
+  virtual void VisitPushArgument(PushArgumentInstr* bind);
+
+  const ParsedFunction& parsed_function_;
+  FlowGraph* flow_graph_;
+  bool still_changing_;
+  DISALLOW_COPY_AND_ASSIGN(FlowGraphTypePropagator);
+};
+
+
 // Loop invariant code motion.
 class LICM : public AllStatic {
  public: