Implement eager instantiation and canonicalization of type arguments at run

runtime/vm/flow_graph_compiler.cc

Index: runtime/vm/flow_graph_compiler.cc
===================================================================
--- runtime/vm/flow_graph_compiler.cc	(revision 32446)
+++ runtime/vm/flow_graph_compiler.cc	(working copy)
@@ -1254,8 +1254,8 @@
     // arguments.
     const intptr_t num_type_params = type_class.NumTypeParameters();
     const intptr_t from_index = num_type_args - num_type_params;
-    const AbstractTypeArguments& type_arguments =
-        AbstractTypeArguments::Handle(type.arguments());
+    const TypeArguments& type_arguments =
+        TypeArguments::Handle(type.arguments());
     const bool is_raw_type = type_arguments.IsNull() ||
         type_arguments.IsRaw(from_index, num_type_params);
     return is_raw_type;