PR gdb/14288

    PR gdb/14288
        * c-valprint.c (c_val_print): For character arrays
        with "print null" option on, print ellipses if
        the output is truncated and the next character is not \000.
        * valprint.c (MAX_WCHARS): Define.
        (WCHAR_BUFLEN): Likewise.
        (WCHAR_BUFLEN_MAX): Likewise.
        (struct converted_character): New structure.
        (count_next_character): New function.
        (print_converted_chars_to_obstack): New function.
        (generic_printstr): Rewrite using count_next_character
        and print_converted_chars_to_obstack.

        * gdb.base/printcmds.c: Add invalid_XXX globals
        for repeated byte tests.
        * gdb.base/printcmds.exp (test_repeat_bytes): New procedure.
        * gdb.base/wchar.c (main): Add and construct a wchar_t
        array with repeated characters.
        * gdb.base/wchar.exp: Add repeated character tests.