PATCH V2 [2/10] arm: add 'pacbti' instruction for Armv8.1-M pacbti extension

[Nick Clifton]

Hi Andrea,

> second patch of the series adding support for PACBTI for Cortex-M.
> 
> See:
> - Armv8.1-M Pointer Authentication and Branch Target Identification Extension [1]
> - Armv8-M Architecture Reference Manual [2]
> 
> This is to add the 'pacbti' instruction.
> 
> This version is incorporating Nick suggestion to skip the
> armv8_1-m-pacbti-bad test on PE format targets.

Approved - please apply.

Cheers
   Nick