Deparameterize Results and ResultsCursor.

They both now only ever contain a `Results<'tcx, A>`.

This means `AnalysisResults` can be removed, as can many
`borrow`/`borrow_mut` calls. Also `Results` no longer needs a
`PhantomData` because `'tcx` is now named by `entry_sets`.

compiler/rustc_mir_dataflow/src/framework/mod.rs

@@ -47,7 +47,7 @@ mod visitor;
 
 pub use self::cursor::ResultsCursor;
 pub use self::direction::{Backward, Direction, Forward};
-pub use self::engine::{Engine, EntrySets, Results};
+pub use self::engine::{Engine, Results};
 pub use self::lattice::{JoinSemiLattice, MaybeReachable};
 pub use self::visitor::{visit_results, ResultsVisitable, ResultsVisitor};