Replace OS::MemCopy with OS::MemMove (just as fast but more flexible).

src/elements.cc

 // Copyright 2012 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 165 matching lines @@
          (copy_size + static_cast<int>(from_start)) <= from_base->length());
   if (copy_size == 0) return;
   FixedArray* from = FixedArray::cast(from_base);
   FixedArray* to = FixedArray::cast(to_base);
   ASSERT(IsFastSmiOrObjectElementsKind(from_kind));
   ASSERT(IsFastSmiOrObjectElementsKind(to_kind));
   Address to_address = to->address() + FixedArray::kHeaderSize;
   Address from_address = from->address() + FixedArray::kHeaderSize;
   CopyWords(reinterpret_cast<Object**>(to_address) + to_start,
             reinterpret_cast<Object**>(from_address) + from_start,
-            copy_size);
+            static_cast<size_t>(copy_size));
   if (IsFastObjectElementsKind(from_kind) &&
       IsFastObjectElementsKind(to_kind)) {
     Heap* heap = from->GetHeap();
     if (!heap->InNewSpace(to)) {
       heap->RecordWrites(to->address(),
                          to->OffsetOfElementAt(to_start),
                          copy_size);
     }
     heap->incremental_marking()->RecordWrites(to);
   }
@@ skipping 135 matching lines @@
   if (copy_size == 0) return;
   FixedDoubleArray* from = FixedDoubleArray::cast(from_base);
   FixedDoubleArray* to = FixedDoubleArray::cast(to_base);
   Address to_address = to->address() + FixedDoubleArray::kHeaderSize;
   Address from_address = from->address() + FixedDoubleArray::kHeaderSize;
   to_address += kDoubleSize * to_start;
   from_address += kDoubleSize * from_start;
   int words_per_double = (kDoubleSize / kPointerSize);
   CopyWords(reinterpret_cast<Object**>(to_address),
             reinterpret_cast<Object**>(from_address),
-            words_per_double * copy_size);
+            static_cast<size_t>(words_per_double * copy_size));
 }
 
 
 static void CopySmiToDoubleElements(FixedArrayBase* from_base,
                                     uint32_t from_start,
                                     FixedArrayBase* to_base,
                                     uint32_t to_start,
                                     int raw_copy_size) {
   int copy_size = raw_copy_size;
   if (raw_copy_size < 0) {
@@ skipping 1711 matching lines @@
       UNREACHABLE();
       break;
   }
 
   array->set_elements(elms);
   array->set_length(Smi::FromInt(number_of_elements));
   return array;
 }
 
 } }  // namespace v8::internal