Free one bit in Map by removing unused retaining counter.

src/objects-printer.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/objects.h"
 
 #include "src/disasm.h"
 #include "src/disassembler.h"
 #include "src/interpreter/bytecodes.h"
 #include "src/objects-inl.h"
@@ skipping 466 matching lines @@
   int nof_transitions = TransitionArray::NumberOfTransitions(raw_transitions());
   if (nof_transitions > 0) {
     os << "\n - transitions #" << nof_transitions << ": "
        << Brief(raw_transitions());
     TransitionArray::PrintTransitions(os, raw_transitions(), false);
   }
   os << "\n - prototype: " << Brief(prototype());
   os << "\n - constructor: " << Brief(GetConstructor());
   os << "\n - code cache: " << Brief(code_cache());
   os << "\n - dependent code: " << Brief(dependent_code());
-  os << "\n - counter: " << counter();
+  os << "\n - construction counter: " << construction_counter();
   os << "\n";
 }
 
 
 void CodeCache::CodeCachePrint(std::ostream& os) {  // NOLINT
   HeapObject::PrintHeader(os, "CodeCache");
   os << "\n - default_cache: " << Brief(default_cache());
   os << "\n - normal_type_cache: " << Brief(normal_type_cache());
 }
 
@@ skipping 815 matching lines @@
 void JSObject::PrintTransitions(std::ostream& os) {  // NOLINT
   Object* transitions = map()->raw_transitions();
   int num_transitions = TransitionArray::NumberOfTransitions(transitions);
   if (num_transitions == 0) return;
   os << "\n - transitions";
   TransitionArray::PrintTransitions(os, transitions, false);
 }
 #endif  // defined(DEBUG) || defined(OBJECT_PRINT)
 }  // namespace internal
 }  // namespace v8