ARM64 support

[JoelLinn]

Unfortunately this does not support ARM64 (or any non x86-64 architecture)

[zyedidia]

Yes, there are a few x86-64-specific things in the codebase. In particular, the interrupt instruction that is used to return control to perforator when a traced function is entered is architecture-specific (defined here), and the function for determining the return address of a stack frame (defined here. The code also uses an x86-64 ptrace regs struct. If these parts are updated, I think perforator could work on ARM as well, but I have no plans to implement this myself.