Update handling of ambiguous name references

runtime/vm/flow_graph_compiler.cc

 // Copyright (c) 2013, 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/globals.h"  // Needed here to get TARGET_ARCH_XXX.
 
 #include "vm/flow_graph_compiler.h"
 
 #include "vm/cha.h"
 #include "vm/dart_entry.h"
@@ skipping 71 matching lines @@
       is_optimizing_(is_optimizing),
       may_reoptimize_(false),
       double_class_(Class::ZoneHandle(
           Isolate::Current()->object_store()->double_class())),
       float32x4_class_(Class::ZoneHandle(
           Isolate::Current()->object_store()->float32x4_class())),
       uint32x4_class_(Class::ZoneHandle(
           Isolate::Current()->object_store()->uint32x4_class())),
       list_class_(Class::ZoneHandle(
           Library::Handle(Library::CoreLibrary()).
-              LookupClass(Symbols::List(), NULL))),
+              LookupClass(Symbols::List()))),
       parallel_move_resolver_(this),
       pending_deoptimization_env_(NULL) {
   ASSERT(assembler != NULL);
   ASSERT(!list_class_.IsNull());
 }
 
 
 bool FlowGraphCompiler::HasFinally() const {
   return parsed_function().function().has_finally();
 }
@@ skipping 997 matching lines @@
 
   for (int i = 0; i < len; i++) {
     sorted->Add(CidTarget(ic_data.GetReceiverClassIdAt(i),
                           &Function::ZoneHandle(ic_data.GetTargetAt(i)),
                           ic_data.GetCountAt(i)));
   }
   sorted->Sort(HighestCountFirst);
 }
 
 }  // namespace dart