changelog: [`await_holding_invalid_type`]
This lint allows users to create a denylist of types which are not allowed to be
held across await points. This is essentially a re-implementation of the
language-level [`must_not_suspend`
lint](https://github.com/rust-lang/rust/issues/83310). That lint has a lot of
work still to be done before it will reach Rust stable, and in the meantime
there are a lot of types which can trip up developers if they are used
improperly.
This commit makes `AdtDef` use `Interned`. Much the commit is tedious
changes to introduce getter functions. The interesting changes are in
`compiler/rustc_middle/src/ty/adt.rs`.
