5d1d384443
Because the corresponding `Level` is `DelayedBug` and `span_delayed_bug` follows the pattern used everywhere else: `span_err`, `span_warning`, etc.
Each of these needs to be in a separate file,
because the span_delayed_bug
ICE in rustdoc won't be triggerred
if even a single other error was emitted.
However, conceptually they are all testing basically the same thing. See https://github.com/rust-lang/rust/pull/73566#issuecomment-653689128 for more details.