added wxABI_VERSION test around ToDouble()

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@35325 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/longlong.h

@@ -164,8 +164,10 @@ public:
         return (long)m_ll;
     }
 
+#if wxABI_VERSION >= 20602
         // convert to double
     double ToDouble() const { return m_ll; }
+#endif // ABI >= 2.6.2
 
     // don't provide implicit conversion to wxLongLong_t or we will have an
     // ambiguity for all arithmetic operations
@@ -593,8 +595,10 @@ public:
         return (long)m_lo;
     }
 
+#if wxABI_VERSION >= 20602
         // convert to double
     double ToDouble() const;
+#endif // ABI >= 2.6.2
 
     // operations
         // addition