PATCH: Support armv6-m in libgloss

[Bin Cheng]

> 
>   Sorry for taking so long to review this patch.  Jeff asked me to look
>   at it last week, but I was on holiday and I have only just got back...
> 
>   Anyway the patch is fine.  Thanks very much for taking the time to
>   sort all of this out.  I have applied the patch to the libgloss
>   sources so you should be able to see it there now.
> 
> Cheers
>   Nick
> 
Hi Nick,

Thanks very much for reviewing it.
I have noticed that previous libgloss patches were trying to keep 
libc/sys/arm and libgloss synchronized, though they are not now.
I briefly know that libgloss is separated from newlib before, and
the rest of newlib is left there to support legacy usage.
So, I'm wondering whether this patch should do this?

Thanks-chengbin