Don't force-export V8 symbols unless v8 is built as a shared library.

include/v8-debug.h

 // Copyright 2008 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 37 matching lines @@
 #elif USING_V8_SHARED
 #define EXPORT __declspec(dllimport)
 #else
 #define EXPORT
 #endif
 
 #else  // _WIN32
 
 // Setup for Linux shared library export. See v8.h in this directory for
 // information on how to build/use V8 as shared library.
-#if defined(__GNUC__) && (__GNUC__ >= 4)
+#if defined(__GNUC__) && (__GNUC__ >= 4) && defined(V8_SHARED)
 #define EXPORT __attribute__ ((visibility("default")))
 #else  // defined(__GNUC__) && (__GNUC__ >= 4)
 #define EXPORT
 #endif  // defined(__GNUC__) && (__GNUC__ >= 4)
 
 #endif  // _WIN32
 
 
 /**
  * Debugger support for the V8 JavaScript engine.
@@ skipping 172 matching lines @@
 };
 
 
 }  // namespace v8
 
 
 #undef EXPORT
 
 
 #endif  // V8_V8_DEBUG_H_