Reduce diff to upstream re2 a bit.

third_party/re2/util/stringprintf.cc

 // Copyright 2002 The RE2 Authors.  All Rights Reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 #include "util/util.h"
 
-#ifndef va_copy
-#define va_copy(d,s) ((d) = (s)) //KLUGE: for MS compilers
-#endif
-
 namespace re2 { 
 
 static void StringAppendV(string* dst, const char* format, va_list ap) {
   // First try with a small fixed size buffer
   char space[1024];
 
   // It's possible for methods that use a va_list to invalidate
   // the data in it upon use.  The fix is to make a copy
   // of the structure before using it and use that copy instead.
   va_list backup_ap;
@@ skipping 52 matching lines @@
 }
 
 void StringAppendF(string* dst, const char* format, ...) {
   va_list ap;
   va_start(ap, format);
   StringAppendV(dst, format, ap);
   va_end(ap);
 }
 
 }  // namespace re2