f5193a9fcc
Neither require nor imply lifetime bounds on opaque type for well formedness The actual hidden type can live arbitrarily longer than any individual lifetime and arbitrarily shorter than all but one of the lifetimes. fixes #86218 fixes #84305 This is a **breaking change** but it is a necessary soundness fix
For high-level intro to how type checking works in rustc, see the type checking chapter of the rustc dev guide.