[turbofan] Remove value numbering from late optimization pass.

Review-Url: https://codereview.chromium.org/2570813002
Cr-Commit-Position: refs/heads/master@{#41672}

src/compiler/pipeline.cc

@@ -1133,7 +1133,6 @@ struct LateOptimizationPhase {
                                                    data->jsgraph(), temp_zone);
     DeadCodeElimination dead_code_elimination(&graph_reducer, data->graph(),
                                               data->common());
-    ValueNumberingReducer value_numbering(temp_zone, data->graph()->zone());
     MachineOperatorReducer machine_reducer(data->jsgraph());
     CommonOperatorReducer common_reducer(&graph_reducer, data->graph(),
                                          data->common(), data->machine());
@@ -1142,7 +1141,6 @@ struct LateOptimizationPhase {
     TailCallOptimization tco(data->common(), data->graph());
     AddReducer(data, &graph_reducer, &branch_condition_elimination);
     AddReducer(data, &graph_reducer, &dead_code_elimination);
-    AddReducer(data, &graph_reducer, &value_numbering);
     AddReducer(data, &graph_reducer, &machine_reducer);
     AddReducer(data, &graph_reducer, &common_reducer);
     AddReducer(data, &graph_reducer, &select_lowering);