Tool crashed when project uses std::sync::atomic::AtomicU64

Caught panic trying to run tool with binary depending on atomic primitive AtomicU64:
```
thread 'main' panicked at 'No DW_AT_low_pc attribute found for function _ZN4core4sync6atomic11AtomicUsize4load17h6a7ef750e69dfd6eE', lib/callgraph/src/callgraph/mod.rs:286:13
```