PR 22429

        * fold-const.c (build_range_check): Use unsigned when signed
        overflow is undefined also.  If etype is subtype, make sure that
        the subtraction is in the supertype.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@106400 138bc75d-0d04-0410-961f-82ee72b054a4