Hi,

A little bit of polishing around arm/thumb attribute_target emission and 
testing: Since the arch mode is emitted for each function, the file 
setting becomes useless or redundant.

for example with attr_thumb.c:

=>	.arm
=>	.syntax divided
	.file	"attr_thumb.c"
	.text
	.align	2
	.global	foo
=>	.syntax unified
=>	.code	16
	.thumb_func
	.type	foo, %function

This patch cleans this up and relaxes the attribute target tests to run 
on any thumb1/thumb2.

no new failure on arm-cortex-linux-gnueabi

and arm-none-eabi for
       arm-sim/
       arm-sim//-march=armv7-a
       arm-sim//-mthumb
       arm-sim//-mthumb/-march=armv7-a
       arm-sim/-mflip-thumb/
       arm-sim/-mflip-thumb//-march=armv7-a
       arm-sim/-mflip-thumb//-mthumb
       arm-sim/-mflip-thumb//-mthumb/-march=armv7-a

is still running but OK so far. OK for trunk once done ?

many thanks,

Christian