Use Object::null_instance and Object::null_function and do not create Handles everytime.

runtime/vm/object.cc

Index: runtime/vm/object.cc
diff --git a/runtime/vm/object.cc b/runtime/vm/object.cc
index 4d643122d6564aa4e34fcfccc5ec4b737f273981..cc937270bd5fb7d3024de71bbba4ad4b651dbe55 100644
--- a/runtime/vm/object.cc
+++ b/runtime/vm/object.cc
@@ -94,6 +94,7 @@ Object* Object::null_object_ = NULL;
 Array* Object::null_array_ = NULL;
 String* Object::null_string_ = NULL;
 Instance* Object::null_instance_ = NULL;
+Function* Object::null_function_ = NULL;
 TypeArguments* Object::null_type_arguments_ = NULL;
 Array* Object::empty_array_ = NULL;
 Array* Object::zero_array_ = NULL;
@@ -423,6 +424,7 @@ void Object::InitOnce(Isolate* isolate) {
   null_array_ = Array::ReadOnlyHandle();
   null_string_ = String::ReadOnlyHandle();
   null_instance_ = Instance::ReadOnlyHandle();
+  null_function_ = Function::ReadOnlyHandle();
   null_type_arguments_ = TypeArguments::ReadOnlyHandle();
   empty_array_ = Array::ReadOnlyHandle();
   zero_array_ = Array::ReadOnlyHandle();
@@ -447,6 +449,7 @@ void Object::InitOnce(Isolate* isolate) {
   *null_array_ = Array::null();
   *null_string_ = String::null();
   *null_instance_ = Instance::null();
+  *null_function_ = Function::null();
   *null_type_arguments_ = TypeArguments::null();
 
   // Initialize the empty and zero array handles to null_ in order to be able to
@@ -769,6 +772,8 @@ void Object::InitOnce(Isolate* isolate) {
   ASSERT(null_string_->IsString());
   ASSERT(!null_instance_->IsSmi());
   ASSERT(null_instance_->IsInstance());
+  ASSERT(!null_function_->IsSmi());
+  ASSERT(null_function_->IsFunction());
   ASSERT(!null_type_arguments_->IsSmi());
   ASSERT(null_type_arguments_->IsTypeArguments());
   ASSERT(!empty_array_->IsSmi());
@@ -7249,7 +7254,7 @@ RawField* Field::New(const String& name,
   result.set_owner(owner);
   result.set_token_pos(token_pos);
   result.set_has_initializer(false);
-  result.set_initializer(Function::Handle());
+  result.set_initializer(Object::null_function());

[srdjan, 2015/08/13 15:49:01]

Is this necessary at all, since all data is initialized to Object::null() at
allocation.

[siva, 2015/08/13 16:52:02]

That is a good point, not sure why it was there in the first place, I should
other ::New functions to see if we have a pattern of people initializing with
null object.

   result.set_is_unboxing_candidate(true);
   result.set_guarded_cid(FLAG_use_field_guards ? kIllegalCid : kDynamicCid);
   result.set_is_nullable(FLAG_use_field_guards ? false : true);