Work around broken MSVC standard library

Change-Id: I9bbe6d231cc784f786dc5e31a641b8789fc35eb9
diff --git a/include/vcl/vclptr.hxx b/include/vcl/vclptr.hxx
index c1b1fb6..372b817 100644
--- a/include/vcl/vclptr.hxx
+++ b/include/vcl/vclptr.hxx
@@ -229,8 +229,15 @@ public:
        To avoid confusion whether it returns the address of either the
        pointed-to raw object (for which to use VclPtr::get instead) or the
        wrapper itself (for which to use std::addressof instead).

        (Cannot be deleted at least with MSVC 12, as at least the innards of
        std::stable_sort on a std::vector<VclPtr<T>>, as called from
        TaskPaneList::FindNextSplitter in vcl/source/window/taskpanelist.cxx
        require an address-of operator for VclPtr<T>.)
     */
#if !defined _MSC_VER
    void operator &() = delete;
#endif
}; // class VclPtr

template<typename T1, typename T2>