* diagnostic.c (output_to_stream): Rename to
	output_buffer_to_stream. Loses the stream parameter.
	(init_output_buffer): Set diagnosic_buffer's stream.
	(flush_diagnostic_buffer): Adjust.
	(default_print_error_function): Likewise.
	(finish_diagnostic): Likewise.
	(verbatim): Likewise.

	* diagnostic.h (struct output_buffer): Add `stream' field.
	(output_buffer_attached_stream): New macro.

From-SVN: r39999