Create a build_config header file.

src/include/portability.h

 /*
  * Copyright (c) 2012 The Native Client Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 /*
  * This file should be at the top of the #include group, followed by
  * standard system #include files, then by native client specific
  * includes.
  *
  * TODO(gregoryd): explain why.  (Something to do with windows include
  * files, to be reconstructed.)
  */
 
 #ifndef NATIVE_CLIENT_SRC_INCLUDE_PORTABILITY_H_
 #define NATIVE_CLIENT_SRC_INCLUDE_PORTABILITY_H_ 1
 
 #include <stdlib.h>
 
 #include "native_client/src/include/nacl_base.h"
+#include "native_client/src/include/build_config.h"
 #ifdef __native_client__
 #include <bits/wordsize.h>
 #else
 #include "native_client/src/trusted/service_runtime/include/bits/wordsize.h"
 #endif
 
 #include "native_client/src/include/nacl_compiler_annotations.h"
 
 #if NACL_WINDOWS
 /* disable warnings for deprecated functions like getenv, etc. */
@@ skipping 257 matching lines @@
  * macros for run-time error detectors (such as Valgrind/Memcheck).
  */
 #if defined(_DEBUG) && NACL_LINUX
 #include "native_client/src/third_party/valgrind/memcheck.h"
 #define NACL_MAKE_MEM_UNDEFINED(a, b) (void) VALGRIND_MAKE_MEM_UNDEFINED(a, b)
 #else
 #define NACL_MAKE_MEM_UNDEFINED(a, b)
 #endif
 
 #endif  /* NATIVE_CLIENT_SRC_INCLUDE_PORTABILITY_H_ */