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

src/prettyprinter.cc

Index: src/prettyprinter.cc
diff --git a/src/prettyprinter.cc b/src/prettyprinter.cc
index 50a71ced3d2998fd9c4fad68ceb606e206f2beb8..4660c0fde11ef8d8e496d72d291d989877b60dbc 100644
--- a/src/prettyprinter.cc
+++ b/src/prettyprinter.cc
@@ -505,7 +505,7 @@ void PrettyPrinter::Print(const char* format, ...) {
       const int slack = 32;
       int new_size = size_ + (size_ >> 1) + slack;
       char* new_output = NewArray<char>(new_size);
-      memcpy(new_output, output_, pos_);
+      OS::MemCopy(new_output, output_, pos_);
       DeleteArray(output_);
       output_ = new_output;
       size_ = new_size;