* generic/gdbtk-register.c (map_arg): New data type

    * generic/gdbtk-register.c (map_arg): New data type
        for passing arguments to mapping functions.
        (map_func): New definition of mapping function.
        Changed all callers to use these new types.
        * generic/gdbtk-stack.c (gdb_get_vars_command): Change
        cast to int to dereference of int *.
        * generic/gdbtk-wrapper.c: Change all casts to char * for
        results and args to use pointer or integer flavor of
        gdb_wrapper_args.results and .args.
        * generic/gdbtk-wrapper.h: struct gdb_wrapper_arguments
        members result and args now return a union of void * and int.