Fix harmless unused parameter warnings in wxDEBUG_LEVEL==0 build.

These warnings were harmless as they concerned the parameters used inside
wxASSERTs only but there were hundreds if not thousands of them in
wx/strvararg.h alone so all the rest of build output was completely lost in
them.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@65046 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/strvararg.h

@@ -318,7 +318,11 @@ struct wxFormatStringArgumentFinder<wxWCharBuffer>
                           "format specifier doesn't match argument type" ); \
         } while ( wxFalse )
 #else
-    #define wxASSERT_ARG_TYPE(fmt, index, expected_mask)
+    // Just define it to suppress "unused parameter" warnings for the
+    // parameters which we don't use otherwise
+    #define wxASSERT_ARG_TYPE(fmt, index, expected_mask)                      \
+        wxUnusedVar(fmt);                                                     \
+        wxUnusedVar(index)
 #endif // wxDEBUG_LEVEL/!wxDEBUG_LEVEL