…_bound_candidates

…rence

accomodate -> accommodate

`Rustc::emit_diagnostic` reconstructs a diagnostic passed in from the
macro machinery. Currently it uses the type `DiagnosticBuilder<'_,
ErrorGuaranteed>`, which is incorrect, because the diagnostic might be a
warning. And if it is a warning, because of the `ErrorGuaranteed` we end
up calling into `emit_producing_error_guaranteed` and the assertion
within that function (correctly) fails because the level is not an error
level.

The fix is simple: change the type to `DiagnosticBuilder<'_, ()>`. Using
`()` works no matter what the diagnostic level is, and we don't need an
`ErrorGuaranteed` here.

The panic was reported in rust-lang#120576.

PR rust-lang#119097 made the decision to make all `IntoDiagnostic` impls generic,
because this allowed a bunch of nice cleanups. But four hand-written
impls were unintentionally overlooked. This commit makes them generic.

… opaque types

…lcnr

No need to `validate_alias_bound_self_from_param_env` in `assemble_alias_bound_candidates`

We already fully normalize the self type before we reach `assemble_alias_bound_candidates`, so there's no reason to double check that a projection is truly rigid by checking param-env bounds.

I think this is also blocked on us making sure to always normalize opaques: rust-lang#120549.

r? lcnr

…r=lcnr

test that we do not support higher-ranked regions in opaque type inference

We already do all the right checks in `check_opaque_type_parameter_valid`, and we have done so since at least 2 years.

I collected the tests from rust-lang#116935 and rust-lang#100503 and added some more

cc rust-lang#96146

r? `@lcnr`

Fix typo in serialized.rs

accomodate -> accommodate

Fix panic when compiling `Rocket`.

This panic was reported [here](rust-lang#120576 (comment)).

r? `@oli-obk`

Fix typo in metadata.rs doc comment

…r-errors

`DefId`  to `LocalDefId`