Free one bit in Map by removing unused retaining counter.

src/ppc/builtins-ppc.cc

 // Copyright 2014 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.
 
 #if V8_TARGET_ARCH_PPC
 
 #include "src/codegen.h"
 #include "src/debug/debug.h"
 #include "src/deoptimizer.h"
 #include "src/full-codegen/full-codegen.h"
@@ skipping 401 matching lines @@
         // r7: JSObject (tagged)
         // r8: First in-object property of JSObject (not tagged)
         __ LoadRoot(r9, Heap::kUndefinedValueRootIndex);
 
         if (!is_api_function) {
           Label no_inobject_slack_tracking;
 
           MemOperand bit_field3 = FieldMemOperand(r5, Map::kBitField3Offset);
           // Check if slack tracking is enabled.
           __ lwz(r3, bit_field3);
-          __ DecodeField<Map::Counter>(r11, r3);
+          __ DecodeField<Map::ConstructionCounter>(r11, r3);
           // r11: slack tracking counter
           __ cmpi(r11, Operand(Map::kSlackTrackingCounterEnd));
           __ blt(&no_inobject_slack_tracking);
           // Decrease generous allocation count.
-          __ Add(r3, r3, -(1 << Map::Counter::kShift), r0);
+          __ Add(r3, r3, -(1 << Map::ConstructionCounter::kShift), r0);
           __ stw(r3, bit_field3);
 
           // Allocate object with a slack.
           __ lbz(r3, FieldMemOperand(r5, Map::kUnusedPropertyFieldsOffset));
           __ ShiftLeftImm(r3, r3, Operand(kPointerSizeLog2));
           __ sub(r3, r10, r3);
           // r3: offset of first field after pre-allocated fields
           if (FLAG_debug_code) {
             __ cmp(r8, r3);
             __ Assert(le, kUnexpectedNumberOfPreAllocatedPropertyFields);
@@ skipping 1527 matching lines @@
     __ bkpt(0);
   }
 }
 
 
 #undef __
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_PPC