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

src/arm/lithium-codegen-arm.cc

Index: src/arm/lithium-codegen-arm.cc
diff --git a/src/arm/lithium-codegen-arm.cc b/src/arm/lithium-codegen-arm.cc
index 19cef6bd114675d676129043e224aa5871ddc3ed..69b3207f4229d4bd3a9ebbaca253fe3af59121b6 100644
--- a/src/arm/lithium-codegen-arm.cc
+++ b/src/arm/lithium-codegen-arm.cc
@@ -113,7 +113,7 @@ void LCodeGen::Comment(const char* format, ...) {
   // issues when the stack allocated buffer goes out of scope.
   size_t length = builder.position();
   Vector<char> copy = Vector<char>::New(length + 1);
-  memcpy(copy.start(), builder.Finalize(), copy.length());
+  OS::MemCopy(copy.start(), builder.Finalize(), copy.length());
   masm()->RecordComment(copy.start());
 }