* loop.c (loop_dump_aux, debug_loop): New functions.
	(LOOP_BLOCK_NUM_1, LOOP_BLOCK_NUM, LOOP_INSN_UID): New macros.

	* flow.c (flow_loops_dump): Add callback parameter.
	(flow_loop_dump): Add callback parameter and call it.  Move
	loop note debugging code to loop_dump_aux.

	* basic-block.h (flow_loop_dump): Add callback parameter
	(flow_loops_dump): Likewise.

	* toplev.c (rest_of_compilation): Add NULL callback function pointer
	to call to flow_loops_dump.

From-SVN: r35979