ofz#11611 build failure with std::unexpected_handler

Change-Id: I0340ce6b89dd7edb91a4a4e0c1e21aeb307f3d9f
Reviewed-on: https://gerrit.libreoffice.org/64445
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

bridges/source/cpp_uno/gcc3_linux_x86-64/share.hxx

@@ -113,7 +113,7 @@ struct __cxa_exception {
 #endif
     std::type_info * exceptionType;
     void (* exceptionDestructor)(void *);
-    std::unexpected_handler unexpectedHandler;
+    void (*unexpectedHandler)(); // std::unexpected_handler dropped from C++17
     std::terminate_handler terminateHandler;
     __cxa_exception * nextException;
     int handlerCount;