c-parse.in: save and restore warn_pointer_arith on __extension__ along with pedantic.

c-parse.in: save and restore warn_pointer_arith on __extension__ along with pedantic.

       * c-parse.in: save and restore warn_pointer_arith on __extension__
        along with pedantic.
        (SAVE_WARN_FLAGS, RESTORE_WARN_FLAGS): Added.
        Set the type of extension to itype rather than $<itype>1 kludge.
        * extend.texi (Alternate Keywords): Adjust documentation.
        * c-parse.c, c-parse.y, objc-parse.c, objc-parse.y: Rebuilt.

From-SVN: r29588