* doc/invoke.texi (-Wcatch-value=): Document new warning option.

        * c.opt (Wcatch-value=): New C++ warning flag.

        * semantics.c (finish_handler_parms): Warn about non-reference
        * type
        catch handlers.

        * g++.dg/warn/Wcatch-value-1.C: New test.
        * g++.dg/warn/Wcatch-value-2.C: New test.
        * g++.dg/warn/Wcatch-value-3.C: New test.

From-SVN: r248466