Add enough compiler support to compile empty functions on x64.

runtime/vm/flow_graph_builder.h

Index: runtime/vm/flow_graph_builder.h
diff --git a/runtime/vm/flow_graph_builder.h b/runtime/vm/flow_graph_builder.h
index 1d9f7d0621a3ba2b5a0a92180386407aa3012614..30975dd3aea26eb2fbfb1f06ef56fe2f29a42635 100644
--- a/runtime/vm/flow_graph_builder.h
+++ b/runtime/vm/flow_graph_builder.h
@@ -24,6 +24,10 @@ class FlowGraphBuilder: public ValueObject {
 
   void BuildGraph();
 
+  const GrowableArray<BlockEntryInstr*>* blocks() const {
+    return &postorder_block_entries_;
+  }
+
   const ParsedFunction& parsed_function() const { return parsed_function_; }
 
   void Bailout(const char* reason);
@@ -92,6 +96,8 @@ class EffectGraphVisitor : public AstNodeVisitor {
   InstanceCallComp* TranslateComparison(const ComparisonNode& node);
   StoreLocalComp* TranslateStoreLocal(const StoreLocalNode& node);
   StaticCallComp* TranslateStaticCall(const StaticCallNode& node);
+  void TranslateArgumentList(const ArgumentListNode& node,
+                             ZoneGrowableArray<Value*>* values);
 
   void CloseFragment() { exit_ = NULL; }
   intptr_t AllocateTempIndex() { return temp_index_++; }