Fix ARC simulator to build with 4.8 simulator libraries. Includes disabling
simulated calls to stat and fstat (they will abort the simulator).

In main simulator directory:

2013-01-08  Jeremy Bennett <jeremy.bennett@embecosm.com>

	* common/gennltvals.sh: Add "arc" as a target.
	* common/nltvals.sh: Regenerated.

In arc directory

2013-01-08  Jeremy Bennett <jeremy.bennett@embecosm.com>

	* decode5.c, decode6.c, decode7.c: Replace EXTRACT_MSB0_INT with
	EXTRACT_MSB0_SINT throughout.
	* devices.c (device_error): Match function prototype to common
	declaration.
	* sim-main.h <CGEN_INSN_WORD>: Define type.
	* target-io.h: New file (based on old gdb/target-io/arc.h).
	* traps.c: Include local target-io.h instead of
	gdb/target-io/arc.h.
	(arc_syscall): Comment out unlinkable code for stat and fstat and
	abort instead (temporary workaround).