PR target/19636
	PR target/24894
	PR target/31644
	PR target/31786
	* config/avr/avr.c (legitimate_address_p): Fix problem where subreg
	is not recognized as a valid register usage. Allow REG_X to be used
	as a base pointer.
	* config/avr/avr.h (LEGITIMIZE_RELOAD_ADDRESS): Remove code that
	forces a reload when using a base register.

From-SVN: r140360