Remove unnecessary ValueAnalysisWrapper::Direction.

`Forward` is the default.

Author: nnethercote

compiler/rustc_mir_dataflow/src/lib.rs

@@ -25,9 +25,7 @@ pub use self::framework::{
     fmt, lattice, visit_results, Analysis, AnalysisDomain, Direction, GenKill, GenKillAnalysis,
     JoinSemiLattice, MaybeReachable, Results, ResultsCursor, ResultsVisitable, ResultsVisitor,
 };
-use self::framework::{
-    Backward, CloneAnalysis, Forward, ResultsClonedCursor, SwitchIntEdgeEffects,
-};
+use self::framework::{Backward, CloneAnalysis, ResultsClonedCursor, SwitchIntEdgeEffects};
 use self::move_paths::MoveData;
 
 pub mod debuginfo;

compiler/rustc_mir_dataflow/src/value_analysis.rs

@@ -332,8 +332,6 @@ pub struct ValueAnalysisWrapper<T>(pub T);
 impl<'tcx, T: ValueAnalysis<'tcx>> AnalysisDomain<'tcx> for ValueAnalysisWrapper<T> {
     type Domain = State<T::Value>;
 
-    type Direction = crate::Forward;
-
     const NAME: &'static str = T::NAME;
 
     fn bottom_value(&self, _body: &Body<'tcx>) -> Self::Domain {