use int32 values in invalid wxDateTime ctor after r54663 fixes to wxLongLong under LP64 platforms (unfortunately we can't do the same thing as in trunk as this would break ABI because default-constructed wxDateTime objects in the programs compiled against old headers would become different from the ones defined in the new library)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_8_BRANCH@54668 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/datetime.h

@@ -577,7 +577,7 @@ public:
     // ------------------------------------------------------------------------
 
         // default ctor does not initialize the object, use Set()!
-    wxDateTime() { m_time = wxLongLong((long)ULONG_MAX, ULONG_MAX); }
+    wxDateTime() { m_time = wxLongLong(INT_MIN, 0); }
 
         // from time_t: seconds since the Epoch 00:00:00 UTC, Jan 1, 1970)
 #if (!(defined(__VISAGECPP__) && __IBMCPP__ >= 400))