reload1.c (reload_cse_simplify_set): For LOAD_EXTEND_OP, do not "widen" a destination that is already wider than a word.

        * reload1.c (reload_cse_simplify_set): For LOAD_EXTEND_OP, do not
        "widen" a destination that is already wider than a word.  Also do
        not widen if LOAD_EXTEND_OP is NIL for the given mode.

From-SVN: r40510