re PR target/49868 (Implement named address space to place/access data in flash memory)

re PR target/49868 (Implement named address space to place/access data in flash memory)

	PR target/49868
	PR target/52261
	* doc/extend.texi (AVR Named Address Spaces): No more try to fix
	address spaces located outside of device flash.
	* config/avr/avr.h (base_arch_s): Remove field n_segments.
	(mcu_type_s): Add field n_flash.
	* config/avr/avr-devices.c (avr_arch_types): Remove .n_segments.
	Set .have_elpm and .have_elpmx to 1 for avrxmega4 and avrxmega5.
	(AVR_MCU): Add N_FLASH argument.
	* config/avr/avr-mcus.def (AVR_MCU): Add initializer for .n_flash.
	* config/avr/avr-c.c (avr_cpu_cpp_builtins): Only define built-in
	macro __FLASH<n> if that address space makes sense for the device.
	* config/avr/avr.c (avr_out_lpm): Don't try to fix address spaces
	outside of target flash.
	(avr_asm_named_section): Ditto.
	(avr_asm_select_section): Ditto.
	(avr_addr_space_convert): Ditto.
	(avr_emit_movmemhi): Ditto.
	(avr_nonconst_pointer_addrspace, avr_pgm_check_var_decl): Error if
	address space is outside of device flash.
	(avr_insert_attributes): Ditto.
	(avr_xload_libgcc_p): Use avr_current_device->n_flash instead of
	avr_current_arch->n_segments.

From-SVN: r184614