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

src/scanner.h

 // Copyright 2011 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 197 matching lines @@
   static const int kMinConversionSlack = 256;
   static const int kMaxGrowth = 1 * MB;
   inline int NewCapacity(int min_capacity) {
     int capacity = Max(min_capacity, backing_store_.length());
     int new_capacity = Min(capacity * kGrowthFactory, capacity + kMaxGrowth);
     return new_capacity;
   }
 
   void ExpandBuffer() {
     Vector<byte> new_store = Vector<byte>::New(NewCapacity(kInitialCapacity));
-    memcpy(new_store.start(), backing_store_.start(), position_);
+    OS::MemCopy(new_store.start(), backing_store_.start(), position_);
     backing_store_.Dispose();
     backing_store_ = new_store;
   }
 
   void ConvertToUtf16() {
     ASSERT(is_ascii_);
     Vector<byte> new_store;
     int new_content_size = position_ * kUC16Size;
     if (new_content_size >= backing_store_.length()) {
       // Ensure room for all currently read code units as UC16 as well
@@ skipping 313 matching lines @@
   bool has_multiline_comment_before_next_;
   // Whether we scan 'let' as a keyword for harmony block-scoped let bindings.
   bool harmony_scoping_;
   // Whether we scan 'module', 'import', 'export' as keywords.
   bool harmony_modules_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_SCANNER_H_