[turbofan] Remove locally constructed simplified builders.

test/unittests/compiler/js-builtin-reducer-unittest.cc

Index: test/unittests/compiler/js-builtin-reducer-unittest.cc
diff --git a/test/unittests/compiler/js-builtin-reducer-unittest.cc b/test/unittests/compiler/js-builtin-reducer-unittest.cc
index 7555fe8e0ec31a24495c212b4cbfb9b2de91aa68..a44b1d18cd63fd6db613f062ce607920fba36be4 100644
--- a/test/unittests/compiler/js-builtin-reducer-unittest.cc
+++ b/test/unittests/compiler/js-builtin-reducer-unittest.cc
@@ -5,6 +5,7 @@
 #include "src/compiler/js-builtin-reducer.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/node-properties.h"
+#include "src/compiler/simplified-operator.h"
 #include "src/compiler/typer.h"
 #include "src/isolate-inl.h"
 #include "test/unittests/compiler/graph-unittest.h"
@@ -26,7 +27,8 @@ class JSBuiltinReducerTest : public TypedGraphTest {
   Reduction Reduce(Node* node, MachineOperatorBuilder::Flags flags =
                                    MachineOperatorBuilder::Flag::kNoFlags) {
     MachineOperatorBuilder machine(zone(), kMachPtr, flags);
-    JSGraph jsgraph(isolate(), graph(), common(), javascript(), nullptr,
+    SimplifiedOperatorBuilder simplified(zone());
+    JSGraph jsgraph(isolate(), graph(), common(), javascript(), &simplified,
                     &machine);
     // TODO(titzer): mock the GraphReducer here for better unit testing.
     GraphReducer graph_reducer(zone(), graph());