Added wxUnusedVar for Borland and fixed 2 release mode warnings for Borland (patch #835707); Slight code cleanup.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@24508 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/defs.h

@@ -457,8 +457,12 @@ typedef int wxWindowID;
 
 // sometimes the value of a variable is *really* not used, to suppress  the
 // resulting warning you may pass it to this function
+#ifdef __BORLANDC__
+#define wxUnusedVar(identifier) identifier
+#else
 template <class T>
 inline void wxUnusedVar(const T& WXUNUSED(t)) { }
+#endif
 
 // ----------------------------------------------------------------------------
 // compiler specific settings