re PR target/50566 ([avr]: Add support for better logging similar to -mdeb)

re PR target/50566 ([avr]: Add support for better logging similar to -mdeb)

	PR target/50566
	* config.gcc (extra_objs): Add avr-log.o for $target in:
	avr-*-rtems*, avr-*-*.
	* config/avr/t-avr (avr-log.o): New rule to compile...
	* config/avr/avr-log.c: ...this new file.
	* config/avr/avr.opt (mlog=): New option.
	* config/avr/avr-protos.h (avr_edump, avr_fdump): New macros.
	(avr_log_set_caller_e, avr_log_set_caller_f): New prototypes.
	(avr_log_set_avr_log): New prototype.
	(avr_log_t): New typedef.
	(avr_log): New declaration.
	* config/avr/avr.c (avr_option_override): Call avr_log_set_avr_log.

From-SVN: r179344