Cleanup change.

runtime/vm/jit_optimizer.cc

Index: runtime/vm/jit_optimizer.cc
diff --git a/runtime/vm/jit_optimizer.cc b/runtime/vm/jit_optimizer.cc
index 0b9cfea4d123d5c2dd0955545fdb0c22f6044ad4..686adc5110a901bdd00b604e1fea0ea9f1ba4646 100644
--- a/runtime/vm/jit_optimizer.cc
+++ b/runtime/vm/jit_optimizer.cc
@@ -1211,8 +1211,9 @@ RawBool* JitOptimizer::InstanceOfAsBool(
         cls.IsNullClass()
             ? (type_class.IsNullClass() || type_class.IsObjectClass() ||
                type_class.IsDynamicClass())
-            : cls.IsSubtypeOf(TypeArguments::Handle(Z), type_class,
-                              TypeArguments::Handle(Z), NULL, NULL, Heap::kOld);
+            : cls.IsSubtypeOf(Object::null_type_arguments(), type_class,
+                              Object::null_type_arguments(), NULL, NULL,
+                              Heap::kOld);
     results->Add(cls.id());
     results->Add(is_subtype);
     if (prev.IsNull()) {
@@ -1304,8 +1305,8 @@ static bool TryExpandTestCidsResult(ZoneGrowableArray<intptr_t>* results,
     const Class& cls = Class::Handle(class_table.At(kSmiCid));
     const Class& type_class = Class::Handle(type.type_class());
     const bool smi_is_subtype =
-        cls.IsSubtypeOf(TypeArguments::Handle(), type_class,
-                        TypeArguments::Handle(), NULL, NULL, Heap::kOld);
+        cls.IsSubtypeOf(Object::null_type_arguments(), type_class,
+                        Object::null_type_arguments(), NULL, NULL, Heap::kOld);
     results->Add((*results)[results->length() - 2]);
     results->Add((*results)[results->length() - 2]);
     for (intptr_t i = results->length() - 3; i > 1; --i) {