Contribution of PowerPC port (continuation of 422063005) - serialize.cc cleanup

src/heap/mark-compact.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"
 
 #include "src/base/atomicops.h"
 #include "src/base/bits.h"
 #include "src/code-stubs.h"
 #include "src/compilation-cache.h"
@@ skipping 2857 matching lines @@
   static inline void UpdateSlot(Heap* heap, Object** slot) {
     Object* obj = reinterpret_cast<Object*>(
         base::NoBarrier_Load(reinterpret_cast<base::AtomicWord*>(slot)));
 
     if (!obj->IsHeapObject()) return;
 
     HeapObject* heap_obj = HeapObject::cast(obj);
 
 // TODO(ishell): remove, once crbug/454297 is caught.
 #if V8_TARGET_ARCH_64_BIT
+#ifndef V8_OS_AIX  // no point checking on AIX as full 64 range is supported
     const uintptr_t kBoundary = V8_UINT64_C(1) << 48;
     STATIC_ASSERT(kBoundary > 0);
     if (reinterpret_cast<uintptr_t>(heap_obj->address()) >= kBoundary) {
       CheckLayoutDescriptorAndDie(heap, slot);
     }
 #endif
+#endif
     MapWord map_word = heap_obj->map_word();
     if (map_word.IsForwardingAddress()) {
       DCHECK(heap->InFromSpace(heap_obj) ||
              MarkCompactCollector::IsOnEvacuationCandidate(heap_obj));
       HeapObject* target = map_word.ToForwardingAddress();
       base::NoBarrier_CompareAndSwap(
           reinterpret_cast<base::AtomicWord*>(slot),
           reinterpret_cast<base::AtomicWord>(obj),
           reinterpret_cast<base::AtomicWord>(target));
       DCHECK(!heap->InFromSpace(target) &&
@@ skipping 1602 matching lines @@
   SlotsBuffer* buffer = *buffer_address;
   while (buffer != NULL) {
     SlotsBuffer* next_buffer = buffer->next();
     DeallocateBuffer(buffer);
     buffer = next_buffer;
   }
   *buffer_address = NULL;
 }
 }
 }  // namespace v8::internal