Rename HandlerInner::delay_span_bug as HandlerInner::span_delayed_bug.

Because the corresponding `Level` is `DelayedBug` and `span_delayed_bug`
follows the pattern used everywhere else: `span_err`, `span_warning`,
etc.

compiler/rustc_trait_selection/src/traits/query/normalize.rs

@@ -292,7 +292,7 @@ impl<'cx, 'tcx> FallibleTypeFolder<TyCtxt<'tcx>> for QueryNormalizer<'cx, 'tcx>
                     // Rustdoc normalizes possibly not well-formed types, so only
                     // treat this as a bug if we're not in rustdoc.
                     if !tcx.sess.opts.actually_rustdoc {
-                        tcx.sess.delay_span_bug(
+                        tcx.sess.span_delayed_bug(
                             DUMMY_SP,
                             format!("unexpected ambiguity: {c_data:?} {result:?}"),
                         );