Create and cache method extraction stub in the ICData.

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 e2c9cd116669b9e48ac693160377ec7543196a97..bc1692419eed0e9980e41627917d9ab12794bee6 100644
--- a/runtime/vm/flow_graph_optimizer.h
+++ b/runtime/vm/flow_graph_optimizer.h
@@ -89,6 +89,7 @@ class FlowGraphOptimizer : public FlowGraphVisitor {
                         Instruction* deopt_target);
 
   bool InstanceCallNeedsClassCheck(InstanceCallInstr* call) const;
+  bool MethodExtractorNeedsClassCheck(InstanceCallInstr* call) const;
 
   void InlineImplicitInstanceGetter(InstanceCallInstr* call);
   void InlineArrayLengthGetter(InstanceCallInstr* call,
@@ -98,6 +99,8 @@ class FlowGraphOptimizer : public FlowGraphVisitor {
   void InlineGArrayCapacityGetter(InstanceCallInstr* call);
   void InlineStringLengthGetter(InstanceCallInstr* call);
   void InlineStringIsEmptyGetter(InstanceCallInstr* call);
+  void InlineMethodExtractor(InstanceCallInstr* call);
+
 
   FlowGraph* flow_graph_;