[Interpreter] Localize the CanonicalHandleScope to parsing and renumbering.

src/ast/ast-value-factory.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 244 matching lines @@
   // This Vector will be valid as long as the Collector is alive (meaning that
   // the AstRawString will not be moved).
   AstConsString* new_string = new (zone_) AstConsString(left, right);
   CHECK(new_string != nullptr);
   AddString(new_string);
   return new_string;
 }
 
 
 void AstValueFactory::Internalize(Isolate* isolate) {
+  // Create a canonical handle scope if compiling ignition bytecode. This is
+  // required by the constant array builder to de-duplicate objects without
+  // dereferencing handles.
+  std::unique_ptr<CanonicalHandleScope> canonical;
+  if (FLAG_ignition) canonical.reset(new CanonicalHandleScope(isolate));
+
   // Strings need to be internalized before values, because values refer to
   // strings.
   for (AstString* current = strings_; current != nullptr;) {
     AstString* next = current->next();
     current->Internalize(isolate);
     current = next;
   }
   for (AstValue* current = values_; current != nullptr;) {
     AstValue* next = current->next();
     current->Internalize(isolate);
@@ skipping 110 matching lines @@
                                   length) == 0;
     } else {
       return CompareCharsUnsigned(reinterpret_cast<const uint16_t*>(l),
                                   reinterpret_cast<const uint16_t*>(r),
                                   length) == 0;
     }
   }
 }
 }  // namespace internal
 }  // namespace v8