[DynInst_API:] Deletion of the arm64 branch

[Sunny Shah <ssunny@xxxxxxxxxxx>]

Hello,

The arm64 branch, that until now was used for committing changes 
specific to the ARMv8 port of Dyninst, has been brought up to date with 
master and was merged into it yesterday. Keeping in mind our policy on 
branching going ahead (short topic branches created off master and then 
merged back into it after the work on the topic is done), I intend to 
delete the arm64 branch by Thursday morning.
If you still have a requirement for the branch, let me know and we can 
work something out (note that everything in arm64 is currently also in 
master).
Thanks,
Sunny