[arm] fix assembler crash

[Richard Earnshaw]

On Wed, 2010-05-12 at 17:59 +0100, Nathan Sidwell wrote:
> Nathan Sidwell wrote:
> > This patch fixes a bug where the assembler seg faults if you try and use 
> > the thumb-only cbnz or cbz instructions.  It also augments the error 
> > messages emitted when you use a thumb- or arm-only instruction in the 
> > wrong mode.  Rather than claim the cpu doesn't support that instruction, 
> > it now says it doesn't support it *in $FOO mode* (where FOO is Thumb or 
> > ARM as appropriate).
> 
> ping? http://sourceware.org/ml/binutils/2010-05/msg00030.html

I don't particularly like "wide Thumb mode".  Why not just say "Thumb-2
mode"?  

Other than that, this is fine.

R.