Remove unused byte from Map::instance_sizes field.

src/x64/macro-assembler-x64.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/v8.h"
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/base/bits.h"
 #include "src/base/division-by-constant.h"
@@ skipping 4286 matching lines @@
   // Update allocation top.
   UpdateAllocationTopHelper(result_end, scratch, flags);
 
   // Tag the result if requested.
   if ((flags & TAG_OBJECT) != 0) {
     addp(result, Immediate(kHeapObjectTag));
   }
 }
 
 
-void MacroAssembler::UndoAllocationInNewSpace(Register object) {
-  ExternalReference new_space_allocation_top =
-      ExternalReference::new_space_allocation_top_address(isolate());
-
-  // Make sure the object has no tag before resetting top.
-  andp(object, Immediate(~kHeapObjectTagMask));
-  Operand top_operand = ExternalOperand(new_space_allocation_top);
-#ifdef DEBUG
-  cmpp(object, top_operand);
-  Check(below, kUndoAllocationOfNonAllocatedMemory);
-#endif
-  movp(top_operand, object);
-}
-
-
 void MacroAssembler::AllocateHeapNumber(Register result,
                                         Register scratch,
                                         Label* gc_required,
                                         MutableMode mode) {
   // Allocate heap number in new space.
   Allocate(HeapNumber::kSize, result, scratch, no_reg, gc_required, TAG_OBJECT);
 
   Heap::RootListIndex map_index = mode == MUTABLE
       ? Heap::kMutableHeapNumberMapRootIndex
       : Heap::kHeapNumberMapRootIndex;
@@ skipping 758 matching lines @@
   movl(rax, dividend);
   shrl(rax, Immediate(31));
   addl(rdx, rax);
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64