Move V8EXPORT definition to its own file

include/v8.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 20 matching lines @@
  *
  * This set of documents provides reference material generated from the
  * V8 header file, include/v8.h.
  *
  * For other documentation see http://code.google.com/apis/v8/
  */
 
 #ifndef V8_H_
 #define V8_H_
 
+#include "v8-export.h"
 #include "v8stdint.h"
 
-#ifdef _WIN32
-
-// Setup for Windows DLL export/import. When building the V8 DLL the
-// BUILDING_V8_SHARED needs to be defined. When building a program which uses
-// the V8 DLL USING_V8_SHARED needs to be defined. When either building the V8
-// static library or building a program which uses the V8 static library neither
-// BUILDING_V8_SHARED nor USING_V8_SHARED should be defined.
-#if defined(BUILDING_V8_SHARED) && defined(USING_V8_SHARED)
-#error both BUILDING_V8_SHARED and USING_V8_SHARED are set - please check the\
-  build configuration to ensure that at most one of these is set
-#endif
-
-#ifdef BUILDING_V8_SHARED
-#define V8EXPORT __declspec(dllexport)
-#elif USING_V8_SHARED
-#define V8EXPORT __declspec(dllimport)
-#else
-#define V8EXPORT
-#endif  // BUILDING_V8_SHARED
-
-#else  // _WIN32
-
-// Setup for Linux shared library export.
-#if defined(__GNUC__) && ((__GNUC__ >= 4) || \
-    (__GNUC__ == 3 && __GNUC_MINOR__ >= 3)) && defined(V8_SHARED)
-#ifdef BUILDING_V8_SHARED
-#define V8EXPORT __attribute__ ((visibility("default")))
-#else
-#define V8EXPORT
-#endif
-#else
-#define V8EXPORT
-#endif
-
-#endif  // _WIN32
-
 #if defined(__GNUC__) && !defined(DEBUG)
 #define V8_INLINE(declarator) inline __attribute__((always_inline)) declarator
 #elif defined(_MSC_VER) && !defined(DEBUG)
 #define V8_INLINE(declarator) __forceinline declarator
 #else
 #define V8_INLINE(declarator) inline declarator
 #endif
 
 #if defined(__GNUC__) && !V8_DISABLE_DEPRECATIONS
 #define V8_DEPRECATED(declarator) declarator __attribute__ ((deprecated))
@@ skipping 6462 matching lines @@
 
 
 /**
  * \example process.cc
  */
 
 
 }  // namespace v8
 
 
-#undef V8EXPORT
 #undef TYPE_CHECK
 
 
 #endif  // V8_H_