[$] Cleaning up after BPF exceptions

Kumar Kartikeya Dwivedi has been working to add support for exceptions to BPF
since mid-2023. In July, Dwivedi posted

the first patch set in this effort, which adds support for basic stack unwinding.
In February 2024, he posted

the second patch set
aimed at letting the kernel release resources held by the BPF program when an
exception occurs. This makes exceptions usable in many more contexts.