Introduce new language extension name for quick-look impredicativity
See https://github.com/ghc-proposals/ghc-proposals/pull/274#issuecomment-664654358.
Before doing anything we need a consensus on what to do.
See https://github.com/ghc-proposals/ghc-proposals/pull/274#issuecomment-664654358.
Before doing anything we need a consensus on what to do.