Use proper type when applying deref adjustment in const
When applying a deref adjustment to some type `Wrap<T>` which derefs to `T`, we were checking that `T: ~const Deref`, not `Wrap<T>: ~const Deref` like we should have been.
r? project-const-traits
Fixes#136273Fixes#135210 -- I just deleted the test since the regression test is uninteresting