[Patch ARM] Fix build attributes for armv8-a in case of assembler files that contain...

[Patch ARM] Fix build attributes for armv8-a in case of assembler files that contain no directives.

There is currently a problem in the way in which we produce
build attributes for simple assembler files that have armv8-a
instructions.

In these case we need to generate TAG_ISA_THUMB_Use to be Thumb-2
and set the architecture profile to be 'A' rather than not
setting architecture profile to be 'A' and setting TAG_ISA_THUMB_Use
to be Thumb-1.

This is a pre-requisite for any v8-m patches that have been posted.
arm-none-eabi gas testsuite run. no regressions.

2015-12-17  Ramana Radhakrishnan  <ramana.radhakrishnan@arm.com>

	* gas/config/tc-arm.c (aeabi_set_public_attributes): Adjust
	TAG_ARCH_profile for armv8-a.
	* gas/testsuite/gas/arm/armv8a-automatic-hlt.d: New test.
	* gas/testsuite/gas/arm/armv8a-automatic-hlt.s: New test.
	* gas/testsuite/gas/arm/armv8a-automatic-lda.d: New test.
	* gas/testsuite/gas/arm/armv8a-automatic-lda.s: New test.