* c.opt (Wenum-compare): New warning option.
        * doc/invoke.texi (Warning Options): Document -Wenum-compare.

cp/
        * call.c (build_new_op): Make warning conditional on OPT_Wenum_compare.

testsuite/
        * g++.dg/warn/Wenum-compare.C: New testcase.
        * g++.dg/warn/Wenum-compare-no.C: Ditto.

From-SVN: r136035