Make CONST_VTABLE the default in the Wine source.

diff --git a/include/objbase.h b/include/objbase.h
index 6347610..fb2b99a 100644
--- a/include/objbase.h
+++ b/include/objbase.h
@@ -246,6 +246,10 @@
 
 #define interface struct
 
+#ifdef __WINESRC__
+#define CONST_VTABLE
+#endif
+
 #ifdef CONST_VTABLE
 #undef CONST_VTBL
 #define CONST_VTBL const