Remove instantiator argument in generated code for type tests.

runtime/vm/constant_propagator.cc

Index: runtime/vm/constant_propagator.cc
diff --git a/runtime/vm/constant_propagator.cc b/runtime/vm/constant_propagator.cc
index 1b70c96a0544849dcc4a3248332dcb38ae842daf..8792cf549164199d15cb31ac188e5acea040f9c2 100644
--- a/runtime/vm/constant_propagator.cc
+++ b/runtime/vm/constant_propagator.cc
@@ -764,8 +764,7 @@ void ConstantPropagator::VisitInstanceOf(InstanceOfInstr* instr) {
     if (value.IsInstance()) {
       const Instance& instance = Instance::Cast(value);
       const AbstractType& checked_type = instr->type();
-      if (instr->instantiator()->BindsToConstantNull() &&
-          instr->instantiator_type_arguments()->BindsToConstantNull()) {
+      if (instr->instantiator_type_arguments()->BindsToConstantNull()) {
         const TypeArguments& checked_type_arguments = TypeArguments::Handle();
         Error& bound_error = Error::Handle();
         bool is_instance = instance.IsInstanceOf(checked_type,