Make component=shared_library gyp build work for Linux.

src/v8dll-main.cc

Index: src/v8dll-main.cc
===================================================================
--- src/v8dll-main.cc	(revision 7688)
+++ src/v8dll-main.cc	(working copy)
@@ -25,10 +25,11 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+#include "../include/v8.h"
+
+#ifdef WIN32
 #include <windows.h>
 
-#include "../include/v8.h"
-
 extern "C" {
 BOOL WINAPI DllMain(HANDLE hinstDLL,
                     DWORD dwReason,
@@ -37,3 +38,4 @@
   return TRUE;
 }
 }
+#endif