* toplev.c (decode_f_option): Adjust setting.
	(toplev_main): Call diagnostic_initialize.  Remove call to
	reshape_diagnostic_buffer._

	* diagnostic.h (struct output_buffer): Add new field format_decoder.
	(diagnostic_format_decoder): New macro.
	(diagnostic_prefixing_rule): Likewise.
	(diagnostic_line_cutoff): Likewise.
	(set_message_prefixing_rule): Remove.

	* diagnostic.c (lang_printer): Remove.
	(diagnostic_message_length_per_line): Likewise.
	(current_prefixing_rule): Likewise.
	(initialize_diagnostics): Rename to...
	(diagnostic_initialize): ...this. Tweak.
	(default_initialize_buffer): Remove.
	(reshape_diagnostic_buffer): Likewise.
	(init_output_buffer): Adjust prefixing rule setting.
	(output_format): Use format_decoder from the output_buffer.

	* c-lang.c (c_init): Adjust tree formatter setting.

cp/
  	* error.c (init_error): Adjust settings.

From-SVN: r43588