[turbofan] Enforce native context specialization.

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

Index: test/unittests/compiler/js-create-lowering-unittest.cc
diff --git a/test/unittests/compiler/js-create-lowering-unittest.cc b/test/unittests/compiler/js-create-lowering-unittest.cc
index cf2955356484b6dca244167f634f894297e28109..f4a1192abf167bfae8f6a5c7ef497c7e54dcba31 100644
--- a/test/unittests/compiler/js-create-lowering-unittest.cc
+++ b/test/unittests/compiler/js-create-lowering-unittest.cc
@@ -40,8 +40,8 @@ class JSCreateLoweringTest : public TypedGraphTest {
     // TODO(titzer): mock the GraphReducer here for better unit testing.
     GraphReducer graph_reducer(zone(), graph());
     JSCreateLowering reducer(&graph_reducer, &deps_, &jsgraph,
-                             MaybeHandle<LiteralsArray>(),
-                             MaybeHandle<Context>(), zone());
+                             MaybeHandle<LiteralsArray>(), native_context(),
+                             zone());
     return reducer.Reduce(node);
   }