[turbofan] Turn JSContextSpecializer into an AdvancedReducer.

src/compiler/pipeline.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/pipeline.h"
 
 #include <fstream>  // NOLINT(readability/streams)
 #include <sstream>
 
 #include "src/base/adapters.h"
@@ skipping 478 matching lines @@
       data->set_compilation_failed();
     }
   }
 };
 
 
 struct ContextSpecializerPhase {
   static const char* phase_name() { return "context specializing"; }
 
   void Run(PipelineData* data, Zone* temp_zone) {
-    JSContextSpecializer spec(data->jsgraph());
     JSGraphReducer graph_reducer(data->jsgraph(), temp_zone);
+    JSContextSpecializer spec(&graph_reducer, data->jsgraph());
     AddReducer(data, &graph_reducer, &spec);
     graph_reducer.ReduceGraph();
   }
 };
 
 
 struct InliningPhase {
   static const char* phase_name() { return "inlining"; }
 
   void Run(PipelineData* data, Zone* temp_zone) {
@@ skipping 818 matching lines @@
     tcf << AsC1VRegisterAllocationData("CodeGen",
                                        data->register_allocation_data());
   }
 
   data->DeleteRegisterAllocationZone();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8