Use Object::null_object() instead of Object::ZoneHandle() when a null object

runtime/vm/intermediate_language_arm64.cc

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_ARM64.
 #if defined(TARGET_ARCH_ARM64)
 
 #include "vm/intermediate_language.h"
 
 #include "vm/dart_entry.h"
@@ skipping 740 matching lines @@
 }
 
 
 void NativeCallInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   ASSERT(locs()->temp(0).reg() == R1);
   ASSERT(locs()->temp(1).reg() == R2);
   ASSERT(locs()->temp(2).reg() == R5);
   const Register result = locs()->out(0).reg();
 
   // Push the result place holder initialized to NULL.
-  __ PushObject(Object::ZoneHandle(), PP);
+  __ PushObject(Object::null_object(), PP);
   // Pass a pointer to the first argument in R2.
   if (!function().HasOptionalParameters()) {
     __ AddImmediate(R2, FP, (kParamEndSlotFromFp +
                              function().NumParameters()) * kWordSize, PP);
   } else {
     __ AddImmediate(R2, FP, kFirstLocalSlotFromFp * kWordSize, PP);
   }
   // Compute the effective address. When running under the simulator,
   // this is a redirection address that forces the simulator to call
   // into the runtime system.
@@ skipping 1448 matching lines @@
   return locs;
 }
 
 
 void InstantiateTypeInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   const Register instantiator_reg = locs()->in(0).reg();
   const Register result_reg = locs()->out(0).reg();
 
   // 'instantiator_reg' is the instantiator TypeArguments object (or null).
   // A runtime call to instantiate the type is required.
-  __ PushObject(Object::ZoneHandle(), PP);  // Make room for the result.
+  __ PushObject(Object::null_object(), PP);  // Make room for the result.
   __ PushObject(type(), PP);
   __ Push(instantiator_reg);  // Push instantiator type arguments.
   compiler->GenerateRuntimeCall(token_pos(),
                                 deopt_id(),
                                 kInstantiateTypeRuntimeEntry,
                                 2,
                                 locs());
   __ Drop(2);  // Drop instantiator and uninstantiated type.
   __ Pop(result_reg);  // Pop instantiated type.
   ASSERT(instantiator_reg == result_reg);
@@ skipping 47 matching lines @@
   __ CompareImmediate(R1, Smi::RawValue(StubCode::kNoInstantiator), PP);
   __ b(&loop, NE);
   __ b(&slow_case);
   __ Bind(&found);
   __ LoadFromOffset(R0, R2, 1 * kWordSize, PP);  // Cached instantiated args.
   __ b(&type_arguments_instantiated);
 
   __ Bind(&slow_case);
   // Instantiate non-null type arguments.
   // A runtime call to instantiate the type arguments is required.
-  __ PushObject(Object::ZoneHandle(), PP);  // Make room for the result.
+  __ PushObject(Object::null_object(), PP);  // Make room for the result.
   __ PushObject(type_arguments(), PP);
   __ Push(instantiator_reg);  // Push instantiator type arguments.
   compiler->GenerateRuntimeCall(token_pos(),
                                 deopt_id(),
                                 kInstantiateTypeArgumentsRuntimeEntry,
                                 2,
                                 locs());
   __ Drop(2);  // Drop instantiator and uninstantiated type arguments.
   __ Pop(result_reg);  // Pop instantiated type arguments.
   __ Bind(&type_arguments_instantiated);
@@ skipping 34 matching lines @@
   locs->set_in(0, Location::RegisterLocation(R0));
   locs->set_out(0, Location::RegisterLocation(R0));
   return locs;
 }
 
 
 void CloneContextInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   const Register context_value = locs()->in(0).reg();
   const Register result = locs()->out(0).reg();
 
-  __ PushObject(Object::ZoneHandle(), PP);  // Make room for the result.
+  __ PushObject(Object::null_object(), PP);  // Make room for the result.
   __ Push(context_value);
   compiler->GenerateRuntimeCall(token_pos(),
                                 deopt_id(),
                                 kCloneContextRuntimeEntry,
                                 1,
                                 locs());
   __ Drop(1);  // Remove argument.
   __ Pop(result);  // Get result (cloned context).
 }
 
@@ skipping 2986 matching lines @@
   compiler->GenerateCall(token_pos(), &label, stub_kind_, locs());
 #if defined(DEBUG)
   __ LoadImmediate(R4, kInvalidObjectPointer, kNoPP);
   __ LoadImmediate(R5, kInvalidObjectPointer, kNoPP);
 #endif
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM64