[gtk+] Define INITGUID only for mingw.org compiler

[Jan-Joost Spanjers <jspanjers src gnome org>]

commit 6a71820ff399b32c4a95e7b17979513783c4e052
Author: Hib Eris <hib hiberis nl>
Date:   Mon May 13 15:45:18 2013 +0200

    Define INITGUID only for mingw.org compiler
    
    Defining INITGUID causes a build failure with mingw-w64 > r5589.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=699673

 gdk/win32/gdkdnd-win32.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/gdk/win32/gdkdnd-win32.c b/gdk/win32/gdkdnd-win32.c
index 35ab204..6b35059 100644
--- a/gdk/win32/gdkdnd-win32.c
+++ b/gdk/win32/gdkdnd-win32.c
@@ -68,7 +68,11 @@
  *
  */
  
+/* The mingw.org compiler does not export GUIDS in it's import library. To work
+ * around that, define INITGUID to have the GUIDS declared. */
+#if defined(__MINGW32__) && !defined(__MINGW64_VERSION_MAJOR)
 #define INITGUID
+#endif
 
 #include "gdkdnd.h"
 #include "gdkproperty.h"