[PATCH][Binutils][Arm] Fix disassembler crashing on -b binary when thumb file and thumb not forced.

[Tamar Christina]

Hi Christoph,

> 
> I've noticed regressions after your patch on arm-wince-pe:
> FAIL: gas:Undefined binary printing in arm mode
> FAIL: gas:Undefined binary printing in thumb mode
> 
> Christophe

Ah right, the test aren't valid for -pe, I'll widen the skips to exclude *-*-pe instead of
*-unknown-pe and commit it under the obvious rule.

Thanks,
Tamar