Enable variadic macros for VC9 and later.

VC9 and 10 support variadic macros so define HAVE_VARIADIC_MACROS for them
too. This currently only affects wxLog{Debug,Trace} definitions in wx/log.h.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@71436 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/defs.h

@@ -391,6 +391,10 @@ typedef short int WXTYPE;
     #if wxCHECK_WATCOM_VERSION(1,2)
         #define HAVE_VARIADIC_MACROS
     #endif
+
+    #if wxCHECK_VISUALC_VERSION(9)
+        #define HAVE_VARIADIC_MACROS
+    #endif
 #endif /* HAVE_VARIADIC_MACROS */