Remove dead code

Author: slozier

src/core/IronPython/Compiler/Ast/AsyncStatement.cs

@@ -351,11 +351,6 @@ public override bool Walk(AsyncForStatement node) {
             node.Parent = _currentScope;
             return base.Walk(node);
         }
-        // AsyncStatement
-        public override bool Walk(AsyncStatement node) {
-            node.Parent = _currentScope;
-            return base.Walk(node);
-        }
         // AsyncWithStatement
         public override bool Walk(AsyncWithStatement node) {
             node.Parent = _currentScope;

src/core/IronPython/Compiler/Ast/PythonNameBinder.cs

@@ -144,10 +144,6 @@ public virtual void PostWalk(AssignmentStatement node) { }
         public virtual bool Walk(AsyncForStatement node) { return true; }
         public virtual void PostWalk(AsyncForStatement node) { }
 
-        // AsyncStatement
-        public virtual bool Walk(AsyncStatement node) { return true; }
-        public virtual void PostWalk(AsyncStatement node) { }
-
         // AsyncWithStatement
         public virtual bool Walk(AsyncWithStatement node) { return true; }
         public virtual void PostWalk(AsyncWithStatement node) { }
@@ -415,10 +411,6 @@ public override void PostWalk(AssignmentStatement node) { }
         public override bool Walk(AsyncForStatement node) { return false; }
         public override void PostWalk(AsyncForStatement node) { }
 
-        // AsyncStatement
-        public override bool Walk(AsyncStatement node) { return false; }
-        public override void PostWalk(AsyncStatement node) { }
-
         // AsyncWithStatement
         public override bool Walk(AsyncWithStatement node) { return false; }
         public override void PostWalk(AsyncWithStatement node) { }