[turbofan] Revive the useful parts of the SimplifiedOperatorReducer.

src/compiler/pipeline.cc

Index: src/compiler/pipeline.cc
diff --git a/src/compiler/pipeline.cc b/src/compiler/pipeline.cc
index ec1ff39fd9b3020c915fef8c0ea3d7f59b91c647..0d1619a80087f15d9a72f5f8ed2433fd00ac75eb 100644
--- a/src/compiler/pipeline.cc
+++ b/src/compiler/pipeline.cc
@@ -45,6 +45,7 @@
 #include "src/compiler/scheduler.h"
 #include "src/compiler/select-lowering.h"
 #include "src/compiler/simplified-lowering.h"
+#include "src/compiler/simplified-operator-reducer.h"
 #include "src/compiler/tail-call-optimization.h"
 #include "src/compiler/typer.h"
 #include "src/compiler/value-numbering-reducer.h"
@@ -597,12 +598,14 @@ struct SimplifiedLoweringPhase {
     JSGraphReducer graph_reducer(data->jsgraph(), temp_zone);
     DeadCodeElimination dead_code_elimination(&graph_reducer, data->graph(),
                                               data->common());
-    ValueNumberingReducer vn_reducer(temp_zone);
+    SimplifiedOperatorReducer simple_reducer(data->jsgraph());
+    ValueNumberingReducer value_numbering(temp_zone);
     MachineOperatorReducer machine_reducer(data->jsgraph());
     CommonOperatorReducer common_reducer(&graph_reducer, data->graph(),
                                          data->common(), data->machine());
     AddReducer(data, &graph_reducer, &dead_code_elimination);
-    AddReducer(data, &graph_reducer, &vn_reducer);
+    AddReducer(data, &graph_reducer, &simple_reducer);
+    AddReducer(data, &graph_reducer, &value_numbering);
     AddReducer(data, &graph_reducer, &machine_reducer);
     AddReducer(data, &graph_reducer, &common_reducer);
     graph_reducer.ReduceGraph();
@@ -628,13 +631,15 @@ struct ChangeLoweringPhase {
     JSGraphReducer graph_reducer(data->jsgraph(), temp_zone);
     DeadCodeElimination dead_code_elimination(&graph_reducer, data->graph(),
                                               data->common());
-    ValueNumberingReducer vn_reducer(temp_zone);
+    SimplifiedOperatorReducer simple_reducer(data->jsgraph());
+    ValueNumberingReducer value_numbering(temp_zone);
     ChangeLowering lowering(data->jsgraph());
     MachineOperatorReducer machine_reducer(data->jsgraph());
     CommonOperatorReducer common_reducer(&graph_reducer, data->graph(),
                                          data->common(), data->machine());
     AddReducer(data, &graph_reducer, &dead_code_elimination);
-    AddReducer(data, &graph_reducer, &vn_reducer);
+    AddReducer(data, &graph_reducer, &simple_reducer);
+    AddReducer(data, &graph_reducer, &value_numbering);
     AddReducer(data, &graph_reducer, &lowering);
     AddReducer(data, &graph_reducer, &machine_reducer);
     AddReducer(data, &graph_reducer, &common_reducer);