Compilation error on aarch64

[m0nkey653]

Building while targeting aarch64 causes the following compilation error. This looks like it was introduced during #34 refactoring. The GitHub action only uses ubuntu:latest, so build/test for aarch64 isn't run in CI.

error[E0432]: unresolved import `crate::ptrace`
  --> elfcore/src/arch/aarch64.rs:13:12
   |
13 | use crate::ptrace::ptrace_get_reg_set;
   |            ^^^^^^
   |            |
   |            unresolved import
   |            help: a similar path exists: `linux::ptrace`

For more information about this error, try `rustc --explain E0432`.
error: could not compile `elfcore` (lib) due to 1 previous error