Use UniqueSet<T> and Unique<T> in HCheckMaps and HCheckValue.

src/hydrogen-escape-analysis.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 136 matching lines @@
 }
 
 
 // Insert a newly created value check as a replacement for map checks.
 HValue* HEscapeAnalysisPhase::NewMapCheckAndInsert(HCapturedObject* state,
                                                    HCheckMaps* mapcheck) {
   Zone* zone = graph()->zone();
   HValue* value = state->map_value();
   // TODO(mstarzinger): This will narrow a map check against a set of maps
   // down to the first element in the set. Revisit and fix this.
-  Handle<Map> map_object = mapcheck->map_set()->first();
-  UniqueValueId map_id = mapcheck->map_unique_ids()->first();
-  HCheckValue* check = HCheckValue::New(zone, NULL, value, map_object, map_id);
+  HCheckValue* check = HCheckValue::New(
+      zone, NULL, value, mapcheck->first_map(), false);
   check->InsertBefore(mapcheck);
   return check;
 }
 
 
 // Performs a forward data-flow analysis of all loads and stores on the
 // given captured allocation. This uses a reverse post-order iteration
 // over affected basic blocks. All non-escaping instructions are handled
 // and replaced during the analysis.
 void HEscapeAnalysisPhase::AnalyzeDataFlow(HInstruction* allocate) {
@@ skipping 150 matching lines @@
 void HEscapeAnalysisPhase::Run() {
   // TODO(mstarzinger): We disable escape analysis with OSR for now, because
   // spill slots might be uninitialized. Needs investigation.
   if (graph()->has_osr()) return;
   CollectCapturedValues();
   PerformScalarReplacement();
 }
 
 
 } }  // namespace v8::internal