`EvaluatedToUnknown` -> `EvaluatedToAmbigStackDependent`, `EvaluatedToRecur` -> `EvaluatedToErrStackDependent` Less confusing names, since the only difference between them and their parallel `EvalutedTo..` is that they are stack dependent. r? lcnr
HandlerInner::delay_span_bug
HandlerInner::span_delayed_bug
clippy::needless_borrow
alloc_from_iter