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

src/regexp-macro-assembler-irregexp.cc

Index: src/regexp-macro-assembler-irregexp.cc
diff --git a/src/regexp-macro-assembler-irregexp.cc b/src/regexp-macro-assembler-irregexp.cc
index 16766cab0985a1712119edf513a753495c77cc74..e678d607ada0d343ccf041bf9e9bd913a52b1c88 100644
--- a/src/regexp-macro-assembler-irregexp.cc
+++ b/src/regexp-macro-assembler-irregexp.cc
@@ -479,7 +479,7 @@ int RegExpMacroAssemblerIrregexp::length() {
 
 
 void RegExpMacroAssemblerIrregexp::Copy(Address a) {
-  memcpy(a, buffer_.start(), length());
+  OS::MemCopy(a, buffer_.start(), length());
 }
 
 
@@ -488,7 +488,7 @@ void RegExpMacroAssemblerIrregexp::Expand() {
   Vector<byte> old_buffer = buffer_;
   buffer_ = Vector<byte>::New(old_buffer.length() * 2);
   own_buffer_ = true;
-  memcpy(buffer_.start(), old_buffer.start(), old_buffer.length());
+  OS::MemCopy(buffer_.start(), old_buffer.start(), old_buffer.length());
   if (old_buffer_was_our_own) {
     old_buffer.Dispose();
   }