[turbofan] Refactor JSInliner to be a Reducer.

src/compiler/pipeline.cc

Index: src/compiler/pipeline.cc
diff --git a/src/compiler/pipeline.cc b/src/compiler/pipeline.cc
index 1750b7f4e0e5e68a0c58bd79ffa67b952622c442..19f0d6c45d725c0765a5ca3da3ca5a270cc1e18f 100644
--- a/src/compiler/pipeline.cc
+++ b/src/compiler/pipeline.cc
@@ -467,7 +467,9 @@ struct InliningPhase {
     SourcePositionTable::Scope pos(data->source_positions(),
                                    SourcePosition::Unknown());
     JSInliner inliner(temp_zone, data->info(), data->jsgraph());
-    inliner.Inline();
+    GraphReducer graph_reducer(data->graph(), temp_zone);
+    AddReducer(data, &graph_reducer, &inliner);
+    graph_reducer.ReduceGraph();
   }
 };