Implement more of allocation code using type arguments. Type argument extraction for non-factories …

runtime/vm/flow_graph_builder.h

Index: runtime/vm/flow_graph_builder.h
===================================================================
--- runtime/vm/flow_graph_builder.h	(revision 5478)
+++ runtime/vm/flow_graph_builder.h	(working copy)
@@ -114,9 +114,19 @@
                             intptr_t token_index,
                             int start_index);
 
+  // Creates type arguments (one or two values in 'args') used in preparation
+  // of a constructor or factory call.
+  // For factory call instantiates and returns type argument vector in 'args'.
+  // For constructor call returns type arguments and type arguments of the
+  // instantiator.
+  // May be called only if allocating an object of a parameterized class.
   void BuildTypeArguments(ConstructorCallNode* node,
                           ZoneGrowableArray<Value*>* args);
 
+  // Returns the value of the type arguments of the instantiator.
+  Value* GenerateInstantiatorTypeArguments(intptr_t token_index,
+                                           intptr_t type_arguments);
+
   void CloseFragment() { exit_ = NULL; }
   intptr_t AllocateTempIndex() { return temp_index_++; }