Remove `Handler::emit_diag_at_span`.

Compare `Handler::warn` and `Handler::span_warn`. Conceptually they are
almost identical. But their implementations are weirdly different.

`warn`:
- calls `DiagnosticBuilder::<()>::new(self, Warning(None), msg)`, then `emit()`
- which calls `G::diagnostic_builder_emit_producing_guarantee(self)`
- which calls `handler.emit_diagnostic(&mut db.inner.diagnostic)`

`span_warn`:
- calls `self.emit_diag_at_span(Diagnostic::new(Warning(None), msg), span)`
- which calls `self.emit_diagnostic(diag.set_span(sp))`

I.e. they both end up at `emit_diagnostic`, but take very different
routes to get there.

This commit changes `span_*` and similar ones to not use
`emit_diag_at_span`. Instead they just call `struct_span_*` + `emit`.

Some nice side-effects of this:
- `span_fatal` and `span_fatal_with_code` don't need
  `FatalError.raise()`, because `emit` does that.
- `span_err` and `span_err_with_code` doesn't need `unwrap`.
- `struct_span_note`'s `span` arg type is changed from `Span` to
  `impl Into<MultiSpan>` like all the other functions.

0 files changed, 0 insertions, 0 deletions