re PR c++/10784 (Warning about choosing custom operator over copy constructor cannot be turned off (and it's useless in the first place))

cp/
        PR c++/10784
        * call.c (joust): Warn about choosing conversion sequence only if
        -Wconversion.

testsuite/
        * g++.old-deja/g++.benjamin/16077.C: Add -Wconversion option.
        * g++.old-deja/g++.other/conv7.C: Likewise
        * g++.old-deja/g++.other/overcnv2.C: Likewise.
        * g++.old-deja/g++.other/overload14.C: Likewise.

From-SVN: r68312