Create a build_config header file.

src/shared/platform/posix/nacl_error.c

 /*
  * Copyright (c) 2014 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.
  */
 
 #include <errno.h>
 #include <string.h>
 
+#include "native_client/src/include/nacl_defines.h"
 #include "native_client/src/shared/platform/nacl_error.h"
 
 int NaClGetLastErrorString(char* buffer, size_t length) {
 #if defined(__native_client__) || (NACL_LINUX && !NACL_ANDROID)
   char* message;
   /*
    * Note some Linux distributions and newlib provide only the GNU version of
    * strerror_r().
    */
   if (buffer == NULL || length == 0) {
     errno = ERANGE;
     return -1;
   }
   message = strerror_r(errno, buffer, length);
   if (message != buffer) {
     size_t message_bytes = strlen(message) + 1;
     if (message_bytes < length) {
       length = message_bytes;
     }
     memmove(buffer, message, length);
     buffer[length - 1] = '\0';
   }
   return 0;
 #else
   return strerror_r(errno, buffer, length);
 #endif
 }