gcc/
	Add -nodevicespecs option for avr.

	PR target/93182
	* config/avr/avr.opt (-nodevicespecs): New driver option.
	* config/avr/driver-avr.c (avr_devicespecs_file): Only issue
	"-specs=device-specs/..." if that option is not set.
	* doc/invoke.texi (AVR Options) <-nodevicespecs>: Document.

From-SVN: r279995