[heap] Limit friendship of the Heap class to essentials.

src/heap/heap.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/heap/heap.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/base/bits.h"
 #include "src/base/once.h"
@@ skipping 3285 matching lines @@
   Handle<SeededNumberDictionary> slow_element_dictionary =
       SeededNumberDictionary::New(isolate(), 0, TENURED);
   slow_element_dictionary->set_requires_slow_elements();
   set_empty_slow_element_dictionary(*slow_element_dictionary);
 
   set_materialized_objects(*factory->NewFixedArray(0, TENURED));
 
   // Handling of script id generation is in Factory::NewScript.
   set_last_script_id(Smi::FromInt(v8::UnboundScript::kNoScriptId));
 
+  // Allocate the empty script.
+  Handle<Script> script = factory->NewScript(factory->empty_string());
+  script->set_type(Smi::FromInt(Script::TYPE_NATIVE));
+  set_empty_script(*script);
+
   Handle<PropertyCell> cell = factory->NewPropertyCell();
   cell->set_value(Smi::FromInt(Isolate::kArrayProtectorValid));
   set_array_protector(*cell);
 
   cell = factory->NewPropertyCell();
   cell->set_value(the_hole_value());
   set_empty_property_cell(*cell);
 
   set_weak_stack_trace_list(Smi::FromInt(0));
 
@@ skipping 3459 matching lines @@
     *object_type = "CODE_TYPE";                                                \
     *object_sub_type = "CODE_AGE/" #name;                                      \
     return true;
     CODE_AGE_LIST_COMPLETE(COMPARE_AND_RETURN_NAME)
 #undef COMPARE_AND_RETURN_NAME
   }
   return false;
 }
 }  // namespace internal
 }  // namespace v8