Added configure test for const_cast<>(), and enabled it

for MSVC 5 and 6, and MinGW; use const_cast<>() in
wxConstCast if it is available.


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@19537 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

setup.h.in

@@ -150,6 +150,11 @@
  */
 #undef HAVE_EXPLICIT
 
+/*
+ * Define if your compiler supports const_cast<>()
+ */
+#undef HAVE_CONST_CAST
+
 /*
  * Use regex support
  */