Exceptions in BPF

Panics in idiomatic Rust are only caught to prevent them from crossing an FFI boundary, i.e. escaping a Rust callback that’s been called from C. Otherwise, programs can set a global panic handler if the standard one is inadequate, but that is only really used for embedded and other no_std environments.

This saying, the mechanism proposed here is so close to Rust panics (and Go panics) that NOT calling it such will only lead to confusion, esp. when “exception” is such an overloaded term already.