[arm] fix assembler crash

[Nathan Sidwell]

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

nathan

-- 
Nathan Sidwell    ::   http://www.codesourcery.com   ::         CodeSourcery