Upgrade submodule, sync patch and code.

Upgrade submodule, sync patch and code.

Code changes are motivated by:
- gdb struct interp is now a C++ class.
- ui_file is now a C++ class.
- memory ui_file is replaced by new class string_file.

* gdbtk/generic/gdbtk.h: gdbtk_interp renamed to gdbtk_ctl_interp.
  (gdbtk_fputs), (gdbtk_fileopenin): deleted.
  gdbtk_disable_fputs: renamed to gdbtk_disable_write, set to bool.
* gdbtk/generic/gdbtk-bp.c (breakpoint_notify): gdbtk_interp renamed.
* gdbtk/generic/gdbtk-cmds.c (gdbtk_restore_fputs):
  renamed to gdbtk_restore_write.
  (Gdbtk_init): gdbtk_restore_fputs and gdbtk_interp renamed.
  (gdb_eval), (gdb_update_mem):
  use stack-based string file. cleanup chain no longer needed.
* gdbtk/generic/gdbtk-hooks.c: gdbtk_in_fputs renamed.
  Subclass gdbtk_file of ui_file to support console I/O.
  (gdbtk_read): replaced by gdbtk_file::read.
  (gdbtk_fputs): replaced by gdbtk_file::write.
  (gdbtk_two_elem_cmd), (gdbtk_getpid), (report_error),
  (gdbtk_ignorable_warning), (gdbtk_memory_change), (gdbtk_readline_end),
  (gdbtk_call_command), (gdbtk_param_changed), (gdbtk_load_hash),
  (gdbtk_post_add_symbol), (gdbtk_query), (gdbtk_trace_find),
  (gdbtk_trace_start_stop), (gdbtk_annotate_signal), (gdbtk_attach),
  (gdbtk_detach), (gdbtk_architecture_changed): gdbtk_interp renamed.
  (gdbtk_fileopenin): deleted.
  (gdbtk_fileopen): use gdbtk_file subclass object.
  (gdbtk_warning): use ui_file class object for gdb_stderr.
  (x_event): in_fputs renamed. gdbtk_interp renamed.
  (gdbtk_readline): gdbtk_interp renamed. Use gdb_stdout puts method.
* gdbtk/generic/gdbtk-interp.c: New subclass gdbtk_interp of interp.
  Move struct gdbtk_interp_data fields to gdbtk_interp.
  (gdbtk_interpreter_init): replaced by gdbtk_interp::init.
  (gdbtk_interpreter_resume): replaced by gdbtk_interp::resume.
  (gdbtk_interpreter_suspend): replaced by gdbtk_interp::suspend.
  (gdbtk_interpreter_exec): replaced by gdbtk_interp::exec.
  (gdbtk_supports_command_editing): deleted.
  (gdbtk_pre_command_loop): replaced by gdbtk_interp::pre_command_loop.
  gdbtk_interp renamed to gdbtk_tcl_interp.
  (gdbtk_interpreter_ui_out): replaced by gdbtk_interp::interp_ui_out.
  (gdbtk_interp_factory): use new interp class.
* gdbtk/generic/gdbtk-register.c (get_register_size),
  (get_register_collectable), (get_register_types): gdbtk_interp renamed.
  (get_register): gdbtk_interp renamed. Use stack-based memory file.
  Drop obsolete cleanup chain.
* gdbtk/generic/gdbtk-varobj.c (variable_print): Use stack-based memory file.
* gdbtk/generic/gdbtk.c: gdbtk_interp renamed to gdbtk_tcl_interp.
  gdbtk_disable_fputs replaced by gdbtk_disable_write.
  (TclDebug), (cleanup_init), (gdbtk_cleanup), (tk_command), (view_command):
   gdbtk_interp renamed.
  )gdbtk_init): gdbtk_interp and gdbtk_disable_fputs renamed.
* gdbtk/library/interface.tcl (gdbtk_idle), (gdbtk_tcl_fputs):
  gdb_restore_fputs renamed to gdb_restore_write.