This patch adds more devices to avr-mcus.def and regenerates depending files.

There is a new spec function that is the worker for ASM_SPEC and that
transforms -mmcu=device to -mmcu=arch for avr-as.

This transformation was already performed for avr25, avr31, avr35 and avr51 and
is now performed for all devices so that avr-as only need to support -mmcu=arch.

Rationale is to reduce tool dependencies:  as need not to know what device it
compiles for, the core is enough.  The only cases where the core arch is no
enough is

- Tell whether the device suffers from skip silicon bug
- Tell whether the device supporte DES, XCH, LAS, LAC, LAT instruction.

The first case is handled by device_to_as that issues -mno-skip-bug as needed.

The second case is not handled.  Binutils is agnostic w.r.t. availability of
these instructions if the exact device is supplied.  If binutils will wver be
extended to know about these instructions, the preferred way is as described in

http://sourceware.org/PR15043

i.e. add new ISA options to binutils.  That way, tools dependencies can be
disentangled and binutils need not to be changed for every new device.

Ok for trunk?

Even though this is new feature, I'd propose to backport the additions to
avr-mcus.def to 4.7.  The changes to avr-mcus.def are obvious enough, IMO.

Okay to backport avr-mcus.def and docs part to 4.7 then?

Johann

	* config/avr/avr-arch.h (avr_arch_t) <arch_for_as>: New component.
	* config/avr/avr-devices.c: Initialize it.
	* config/avr/avr.h (device_to_arch): Rename to device_to_ld.
	(avr_device_to_arch): Rename to avr_device_to_ld.
	(avr_device_to_as): New prototype.
	(EXTRA_SPEC_FUNCTIONS): Add device_to_as.
	(ASM_SPEC): Use device_to_as to get -mmcu= and -mno-skip-bug=.
	* config/avr/driver-avr.c (avr_device_to_as): New.
	(avr_device_to_arch): Rename to avr_device_to_ld.
	* avr/avr-mcus.def (ata5272, ata5505, attiny1634, ata6285)
	(ata6286, atmega8a, atmega48pa, ata5790, ata5790n, ata5795)
	(atmega164pa, atmega165pa, atmega168pa, atmega16hva, atmega16hvb)
	(atmega16hvbrevb, atmega16m1, atmega16u4, atmega26hvg, atmega32a)
	(atmega32a, atmega3250pa, atmega3290pa, atmega32c1, atmega32m1)
	(atmega32u4, atmega32u6, atmega64a, atmega6490a, atmega6490p)
	(atmega64c1, atmega64m1, atmega64rfa2, atmega64rfr2, atmega32hvb)
	(atmega32hvbrevb, atmega16hva2, atmega48hvf, at90pwm161)
	(atmega128a, atmega1284, atmxt112sl, atmxt224, atmxt224e)
	(atmxt336s, atxmega16a4u, atxmega16c4, atxmega32a4u, atxmega32c4)
	(atxmega32e5, atxmega64a3u, atxmega64a4u, atxmega64b1, atxmega64b3)
	(atxmega64c3, atxmega64d4, atxmega128a3u, atxmega128b1)
	(atxmega128b3, atxmega128c3, atxmega128d4, atmxt540s, atmxt540sreva)
	(atxmega192a3u, atxmega192c3, atxmega256a3u, atxmega256c3)
	(atxmega384c3, atxmega384d3, atxmega128a4u): New AVR_MCU.
	(avrxmega6): Increase max flash segments from 5 to 6.
	* config/avr/t-multilib: Regenerate.
	* config/avr/avr-tables.opt: Regenerate.
	* doc/avr-mmcu.texi: Regenerate.