Under ghc-proposals#366 we are deprecating the special typechecker-assisted name resolution that
DuplicateRecordFields uses for "ambiguous" selectors and updates. In GHC 9.2, a new warning
-Wambiguous-fields will give users advance warning of this change (#18966 (closed), !4770 (closed)).
Under the proposal, a subsequent GHC release will remove support entirely. This will allow us to remove
AmbiguousFieldOcc from the codebase and make consequent simplifications. This ticket is to track this cleanup.