Enhance the array access API to deal with any objct that implements the list interface.

vm/object.cc

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/object.h"
 
 #include "vm/assembler.h"
 #include "vm/assert.h"
 #include "vm/bigint_operations.h"
 #include "vm/bootstrap.h"
@@ skipping 539 matching lines @@
   core_lib.AddClass(cls);
   type = Type::NewNonParameterizedType(cls);
   object_store->set_string_interface(type);
 
   name = String::NewSymbol("bool");
   cls = Class::NewInterface(name, script);
   core_lib.AddClass(cls);
   type = Type::NewNonParameterizedType(cls);
   object_store->set_bool_interface(type);
 
+  name = String::NewSymbol("List");
+  cls = Class::NewInterface(name, script);
+  core_lib.AddClass(cls);
+  type = Type::NewNonParameterizedType(cls);
+  object_store->set_list_interface(type);
+
   // The classes 'Null', 'Dynamic', and 'void' are not registered in the class
   // dictionary and are not named, but corresponding types are stored in the
   // object store.
   cls = null_class_;
   type = Type::NewNonParameterizedType(cls);
   object_store->set_null_type(type);
 
   cls = dynamic_class_;
   type = Type::NewNonParameterizedType(cls);
   object_store->set_dynamic_type(type);
@@ skipping 6217 matching lines @@
   const String& str = String::Handle(pattern());
   const char* format = "JSRegExp: pattern=%s flags=%s";
   intptr_t len = OS::SNPrint(NULL, 0, format, str.ToCString(), Flags());
   char* chars = reinterpret_cast<char*>(
       Isolate::Current()->current_zone()->Allocate(len + 1));
   OS::SNPrint(chars, (len + 1), format, str.ToCString(), Flags());
   return chars;
 }
 
 }  // namespace dart