Undef the macros at the end, as they are not identical (one has an EXPORT)

CGAL_Core/include/CGAL/CORE/CoreDefs.h

@@ -55,7 +55,7 @@
 #else // CGAL_HEADER_ONLY
 
   #define CGAL_GLOBAL_STATE_VAR(TYPE, NAME, VALUE)  \
-    CGAL_CORE_EXPORT extern TYPE NAME;                   \
+    CGAL_EXPORT extern TYPE NAME;                   \
     inline TYPE& get_static_##NAME()                \
     {                                               \
       return NAME;                                  \
@@ -343,4 +343,6 @@ inline void setPositionalFormat(std::ostream& o = std::cout) {
 
 #include <CGAL/enable_warnings.h>
 
+#undef CGAL_GLOBAL_STATE_VAR
+
 #endif // _CORE_COREDEFS_H_

CGAL_ImageIO/include/CGAL/ImageIO/gif_impl.h

@@ -699,3 +699,5 @@ static int GifError(const char *st) {
   return -1;
 }
 
+#undef CGAL_GLOBAL_STATE_VAR
+