Wakeup Tree destructor is recursive, causing issues with large programs

[Redhotsmasher]

These MWEs simply call an external function a million times and seem to consistently trigger a segmentation fault inside Nidhugg. I suspect this might be the/a reason some of my longer tests (> 100000 traces) occasionally crash Nidhugg.
mwes.zip

[margnus1]

While I can't reproduce the problem with "extfunctest.c", the other two seem to cause nidhugg to stack overflow in the recursive destructor for the wakeup tree. I believe this is due to the trace of the program being very long. Of course, we should not do recursion over the length of the trace, but unfortunately we'll have to eschew some of the conveniences of C++ to address this.

In the meantime, if you're on Linux, you can adjust the maximum stack size with ulimit -Ss SIZE_IN_KB. This should workaround the issue. Note that beyond the recursion issue, nidhugg will also misbehave if the trace is longer than 2³¹ LLVM IR instructions.