[turbofan] Turn JSTypedLowering into an AdvancedReducer.

test/unittests/compiler/js-typed-lowering-unittest.cc

Index: test/unittests/compiler/js-typed-lowering-unittest.cc
diff --git a/test/unittests/compiler/js-typed-lowering-unittest.cc b/test/unittests/compiler/js-typed-lowering-unittest.cc
index 55f23a65116f52817785e0324225542c3f694f72..29a4505ae5d788be560e8cb0a26cb1c5560a9d64 100644
--- a/test/unittests/compiler/js-typed-lowering-unittest.cc
+++ b/test/unittests/compiler/js-typed-lowering-unittest.cc
@@ -80,7 +80,9 @@ class JSTypedLoweringTest : public TypedGraphTest {
   Reduction Reduce(Node* node) {
     MachineOperatorBuilder machine(zone());
     JSGraph jsgraph(isolate(), graph(), common(), javascript(), &machine);
-    JSTypedLowering reducer(&jsgraph, zone());
+    // TODO(titzer): mock the GraphReducer here for better unit testing.
+    GraphReducer graph_reducer(graph(), zone());
+    JSTypedLowering reducer(&graph_reducer, &jsgraph, zone());
     return reducer.Reduce(node);
   }