[turbofan] Machine operators are globally shared singletons.

test/cctest/compiler/test-schedule.cc

Index: test/cctest/compiler/test-schedule.cc
diff --git a/test/cctest/compiler/test-schedule.cc b/test/cctest/compiler/test-schedule.cc
index cad686a825eabb7a2380aa3edb757dc972d9d759..6c05c05916fa51c2a46e3e1c3964e6be15e1a612 100644
--- a/test/cctest/compiler/test-schedule.cc
+++ b/test/cctest/compiler/test-schedule.cc
@@ -131,7 +131,7 @@ TEST(BuildMulNodeGraph) {
   Schedule schedule(scope.main_zone());
   Graph graph(scope.main_zone());
   CommonOperatorBuilder common(scope.main_zone());
-  MachineOperatorBuilder machine(scope.main_zone());
+  MachineOperatorBuilder machine;
 
   Node* start = graph.NewNode(common.Start(0));
   graph.SetStart(start);