[PATCH, ARM] Implement __builtin_trap

[Joseph S. Myers]

On Wed, 4 Dec 2013, Ian Bolton wrote:

> The main update, other than cosmetic differences, is that we've chosen
> the same ARM encoding as LLVM for practical purposes.  (The Thumb
> encoding in Mark's patch already matched LLVM.)

Do the encodings match what plain "udf" does in recent-enough gas (too 
recent for us to assume it in GCC or glibc for now), or is it something 
else?

-- 
Joseph S. Myers
joseph@codesourcery.com